go-chi chi before 5.3.0 IP Spoofing via RealIP Middleware
go-chi · chi
Official source article: GitHub GHSA-RJR7-JGGH-PGCP ↗. Check the applicable product and release in the original source.
6.9MediumCVSS 4.0
Recommended action
Patch only the product branches with a verified fix
Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Published severityMedium→Operational priority:High, raised one band.upgradedsince 14 Aug 2026
Evidence used
No CISA KEV confirmation is currently recorded.
A structured source references public exploit or proof-of-concept material.
The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
EPSS is 0.30% for the current model date.
Compensating controls
Validate the affected product branch and deploy the verified fixed release.
Restrict the affected network interface to trusted sources where business-safe.
Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
Confirm that the asset runs go-chi chi and falls inside the recorded affected range.
Verify the installed build against the product-specific fixed version after deployment.
Validate exposure, authentication requirements and compensating controls in the actual environment.
Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Cross-source reconciliation
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Debian Security Tracker: 2 affected package states with no published fix
Distribution package intelligence
Release-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
5 package states
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 2 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
Distribution release
Source package
Vendor state
Fixed version
Evidence
Debian trixietrixie · source
golang-github-go-chi-chi
Affected, no fix publishedDebian currently tracks this release as open.
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
The vendor explicitly identifies these products as affected by this CVE.
cosign as component of SUSE Linux Enterprise Desktop 15 SP7
cosign-bash-completion as component of SUSE Linux Enterprise Desktop 15 SP7
cosign-zsh-completion as component of SUSE Linux Enterprise Desktop 15 SP7
rekor as component of SUSE Linux Enterprise Desktop 15 SP7
cosign as component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
rekor as component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
cosign as component of SUSE Linux Enterprise High Performance Computing 15 SP4
rekor as component of SUSE Linux Enterprise High Performance Computing 15 SP4
cosign as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
rekor as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
warewulf4 as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
warewulf4-dracut as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
Summary
go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.
Remediation
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
CVE-2026-72816 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitygithub.com/go-chi/chi: go-chi/chi: IP Spoofing via RealIP Middleware allows bypassing access controls
32 known affected
The vendor explicitly identifies these products as affected by this CVE.
cryostat/cryostat-storage-rhel9 as a component of Cryostat 4
external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift
gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3
openshift-logging/opa-openshift-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
mta/mta-hub-rhel9 as a component of Migration Toolkit for Applications 8
multicluster-engine/assisted-image-service-rhel8 as a component of Multicluster Engine for Kubernetes
multicluster-engine/assisted-image-service-rhel9 as a component of Multicluster Engine for Kubernetes
openshift-pipelines-client.src as a component of OpenShift Pipelines
openshift-serverless-1/kn-plugin-event-sender-rhel9 as a component of OpenShift Serverless
flightctl-agent as a component of Red Hat Advanced Cluster Management for Kubernetes 2
flightctl-selinux as a component of Red Hat Advanced Cluster Management for Kubernetes 2
flightctl.src as a component of Red Hat Advanced Cluster Management for Kubernetes 2
Summary
A flaw was found in the go-chi/chi RealIP middleware. This vulnerability allows a remote attacker to perform IP spoofing by supplying arbitrary IP addresses in client-controlled headers. This can lead to bypassing IP-based access controls, evading rate limiting and geo-IP restrictions, and polluting audit logs.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2026-58631
No EUVD known-exploited evidence
ENISA has published the identifier mapping but no EUVD description has been stored yet.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix
Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product
01
What, why and how
go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.
What
go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.
Why
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
go-chi/chi through 5.2.1 contains an IP spoofing vulnerability in the RealIP middleware (middleware/realip.go). The realIP() function reads client-controlled headers (True-Client-IP, X-Real-IP, and X-Forwarded-For) and overwrites r.RemoteAddr without verifying that the request originated from a trusted proxy. Attackers can supply arbitrary IP addresses in these headers to bypass IP-based access controls, evade rate limiting and geo-IP restrictions, and pollute audit logs. Fixed in 5.3.0.
Why
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
Likely attack path
a network path → Authentication Bypass by Spoofing → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-290: Authentication Bypass by Spoofing. This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCLowVulnerable-system confidentiality: A successful attack can cause a limited loss.VILowVulnerable-system integrity: A successful attack can cause a limited loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-58631Official EUVD mapping
0 linked advisory records.
Official EUVD record ↗Cyber Security Agency of Singapore · English · CSA-SB-20260819Security Bulletin 19 Aug 2026
The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 19 Aug 2026, published on 19 August 2026. Open the linked bulletin for the product, severity and reference information published in that issue.
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 14 Aug 2026 · Last source change 14 Aug 2026, 15:22 UTC · CWE-290 · Authentication Bypass by Spoofing
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-23
European sourceENISA EUVD · EUVD-2026-58631
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
cryostat/cryostat-storage-rhel9 as a component of Cryostat 4; external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift; gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3; openshift-logging/opa-openshift-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; mta/mta-hub-rhel9 as a component of Migration Toolkit for Applications 8; multicluster-engine/assisted-image-service-rhel8 as a component of Multicluster Engine for Kubernetes; multicluster-engine/assisted-image-service-rhel9 as a component of Multicluster Engine for Kubernetes; openshift-pipelines-client.src as a component of OpenShift Pipelines; openshift-serverless-1/kn-plugin-event-sender-rhel9 as a component of OpenShift Serverless; flightctl-agent as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl-selinux as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/observatorium-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/volsync-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Edge Manager 1; osbuild-composer as a component of Red Hat Enterprise Linux 8; osbuild-composer-core as a component of Red Hat Enterprise Linux 8; osbuild-composer-dnf-json as a component of Red Hat Enterprise Linux 8; osbuild-composer-worker as a component of Red Hat Enterprise Linux 8; osbuild-composer.src as a component of Red Hat Enterprise Linux 8; caddy.src as a component of Red Hat Hardened Images; prometheus3.13.src as a component of Red Hat Hardened Images; prometheus3.5.src as a component of Red Hat Hardened Images; rhoai/odh-model-registry-rhel9 as a component of Red Hat OpenShift AI (RHOAI); cri-o as a component of Red Hat OpenShift Container Platform 4; cri-o.src as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-telemeter as a component of Red Hat OpenShift Container Platform 4; devspaces/udi-rhel9 as a component of Red Hat OpenShift Dev Spaces; rhosdt/tempo-gateway-rhel9 as a component of Red Hat OpenShift distributed tracing 3; quay/quay-rhel8 as a component of Red Hat Quay 3; and 5 more · Fixed: cosign-main@aarch64 as a component of Red Hat Hardened Images; cosign-main@src as a component of Red Hat Hardened Images; cosign-main@x86_64 as a component of Red Hat Hardened Images; spire1-14-main@aarch64 as a component of Red Hat Hardened Images; spire1-14-main@src as a component of Red Hat Hardened Images; spire1-14-main@x86_64 as a component of Red Hat Hardened Images; spire1-15-main@aarch64 as a component of Red Hat Hardened Images; spire1-15-main@src as a component of Red Hat Hardened Images; spire1-15-main@x86_64 as a component of Red Hat Hardened Images
After
cryostat/cryostat-storage-rhel9 as a component of Cryostat 4; external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift; gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3; openshift-logging/opa-openshift-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; mta/mta-hub-rhel9 as a component of Migration Toolkit for Applications 8; multicluster-engine/assisted-image-service-rhel8 as a component of Multicluster Engine for Kubernetes; multicluster-engine/assisted-image-service-rhel9 as a component of Multicluster Engine for Kubernetes; openshift-pipelines-client.src as a component of OpenShift Pipelines; openshift-serverless-1/kn-plugin-event-sender-rhel9 as a component of OpenShift Serverless; flightctl-agent as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl-selinux as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/observatorium-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/volsync-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Edge Manager 1; osbuild-composer as a component of Red Hat Enterprise Linux 8; osbuild-composer-core as a component of Red Hat Enterprise Linux 8; osbuild-composer-dnf-json as a component of Red Hat Enterprise Linux 8; osbuild-composer-worker as a component of Red Hat Enterprise Linux 8; osbuild-composer.src as a component of Red Hat Enterprise Linux 8; rhoai/odh-model-registry-rhel9 as a component of Red Hat OpenShift AI (RHOAI); cri-o as a component of Red Hat OpenShift Container Platform 4; cri-o.src as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-telemeter as a component of Red Hat OpenShift Container Platform 4; devspaces/udi-rhel9 as a component of Red Hat OpenShift Dev Spaces; rhosdt/tempo-gateway-rhel9 as a component of Red Hat OpenShift distributed tracing 3; quay/quay-rhel8 as a component of Red Hat Quay 3; quay/quay-rhel9 as a component of Red Hat Quay 3; satellite/iop-ingress-rhel9 as a component of Red Hat Satellite 6; web-terminal/web-terminal-tooling-rhel9 as a component of Red Hat Web Terminal; and 2 more · Fixed: cosign-main@aarch64 as a component of Red Hat Hardened Images; cosign-main@src as a component of Red Hat Hardened Images; cosign-main@x86_64 as a component of Red Hat Hardened Images; spire1-14-main@aarch64 as a component of Red Hat Hardened Images; spire1-14-main@src as a component of Red Hat Hardened Images; spire1-14-main@x86_64 as a component of Red Hat Hardened Images; spire1-15-main@aarch64 as a component of Red Hat Hardened Images; spire1-15-main@src as a component of Red Hat Hardened Images; spire1-15-main@x86_64 as a component of Red Hat Hardened Images
Affected versionsThe structured affected or fixed version information changed.
Before
cryostat/cryostat-storage-rhel9 as a component of Cryostat 4; external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift; gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3; openshift-logging/opa-openshift-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; mta/mta-hub-rhel9 as a component of Migration Toolkit for Applications 8; multicluster-engine/assisted-image-service-rhel8 as a component of Multicluster Engine for Kubernetes; multicluster-engine/assisted-image-service-rhel9 as a component of Multicluster Engine for Kubernetes; openshift-pipelines-client.src as a component of OpenShift Pipelines; openshift-serverless-1/kn-plugin-event-sender-rhel9 as a component of OpenShift Serverless; flightctl-agent as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl-selinux as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/observatorium-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/volsync-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Edge Manager 1; osbuild-composer as a component of Red Hat Enterprise Linux 8; osbuild-composer-core as a component of Red Hat Enterprise Linux 8; osbuild-composer-dnf-json as a component of Red Hat Enterprise Linux 8; osbuild-composer-worker as a component of Red Hat Enterprise Linux 8; osbuild-composer.src as a component of Red Hat Enterprise Linux 8; caddy.src as a component of Red Hat Hardened Images; cosign.src as a component of Red Hat Hardened Images; prometheus3.13.src as a component of Red Hat Hardened Images; prometheus3.5.src as a component of Red Hat Hardened Images; spire1.14.src as a component of Red Hat Hardened Images; spire1.15.src as a component of Red Hat Hardened Images; rhoai/odh-model-registry-rhel9 as a component of Red Hat OpenShift AI (RHOAI); cri-o as a component of Red Hat OpenShift Container Platform 4; cri-o.src as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-telemeter as a component of Red Hat OpenShift Container Platform 4; and 8 more
After
cryostat/cryostat-storage-rhel9 as a component of Cryostat 4; external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift; gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3; openshift-logging/opa-openshift-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; mta/mta-hub-rhel9 as a component of Migration Toolkit for Applications 8; multicluster-engine/assisted-image-service-rhel8 as a component of Multicluster Engine for Kubernetes; multicluster-engine/assisted-image-service-rhel9 as a component of Multicluster Engine for Kubernetes; openshift-pipelines-client.src as a component of OpenShift Pipelines; openshift-serverless-1/kn-plugin-event-sender-rhel9 as a component of OpenShift Serverless; flightctl-agent as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl-selinux as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/observatorium-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/volsync-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; flightctl.src as a component of Red Hat Edge Manager 1; osbuild-composer as a component of Red Hat Enterprise Linux 8; osbuild-composer-core as a component of Red Hat Enterprise Linux 8; osbuild-composer-dnf-json as a component of Red Hat Enterprise Linux 8; osbuild-composer-worker as a component of Red Hat Enterprise Linux 8; osbuild-composer.src as a component of Red Hat Enterprise Linux 8; caddy.src as a component of Red Hat Hardened Images; prometheus3.13.src as a component of Red Hat Hardened Images; prometheus3.5.src as a component of Red Hat Hardened Images; rhoai/odh-model-registry-rhel9 as a component of Red Hat OpenShift AI (RHOAI); cri-o as a component of Red Hat OpenShift Container Platform 4; cri-o.src as a component of Red Hat OpenShift Container Platform 4; openshift4/ose-telemeter as a component of Red Hat OpenShift Container Platform 4; devspaces/udi-rhel9 as a component of Red Hat OpenShift Dev Spaces; rhosdt/tempo-gateway-rhel9 as a component of Red Hat OpenShift distributed tracing 3; quay/quay-rhel8 as a component of Red Hat Quay 3; and 5 more · Fixed: cosign-main@aarch64 as a component of Red Hat Hardened Images; cosign-main@src as a component of Red Hat Hardened Images; cosign-main@x86_64 as a component of Red Hat Hardened Images; spire1-14-main@aarch64 as a component of Red Hat Hardened Images; spire1-14-main@src as a component of Red Hat Hardened Images; spire1-14-main@x86_64 as a component of Red Hat Hardened Images; spire1-15-main@aarch64 as a component of Red Hat Hardened Images; spire1-15-main@src as a component of Red Hat Hardened Images; spire1-15-main@x86_64 as a component of Red Hat Hardened Images
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.