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Full vulnerability report · 2026
CVE-2025-47911High confidence

Quadratic parsing complexity in golang.org/x/net/html

golang.org/x/net · golang.org/x/net/html

5.3MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. 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
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.57% 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.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs golang.org/x/net golang.org/x/net/html and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

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.

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 releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcegolang-golang-x-netAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcegolang-golang-x-netAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcegolang-golang-x-netVendor fix publishedDebian records a fixed source-package version for this release.1:0.47.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcegolang-golang-x-netVendor fix publishedDebian records a fixed source-package version for this release.1:0.47.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · esm-appsgolang-golang-x-netVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.1:0.21.0+dfsg-1ubuntu0.1~esm2Canonical Ubuntu Security ↗Source updated 5 Oct 2026
Open-source package ranges2 source-attributed ranges

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.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
Gogolang.org/x/net/htmlSEMVER: introduced 0; fixed 0.45.00.45.0OSV record ↗aggregator derived · 10 Sep 2026
gogolang.org/x/net/html< 0.45.00.45.0GitHub advisory ↗github reviewed aggregator · 12 Feb 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2025-47911 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitygolang.org/x/net/html: Quadratic parsing complexity in golang.org/x/net/html
581 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • rhai/assisted-installer-agent-rhel9 as a component of Assisted Installer for Red Hat OpenShift Container Platform 2
  • rhai/assisted-installer-controller-rhel9 as a component of Assisted Installer for Red Hat OpenShift Container Platform 2
  • rhai/assisted-installer-rhel9 as a component of Assisted Installer for Red Hat OpenShift Container Platform 2
  • openshift-builds/openshift-builds-controller-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-git-cloner-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-image-bundler-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-image-processing-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-rhel9-operator as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-shared-resource-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-shared-resource-webhook-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-waiters-rhel9 as a component of Builds for Red Hat OpenShift
  • openshift-builds/openshift-builds-webhook-rhel9 as a component of Builds for Red Hat OpenShift
Summary
The html.Parse function in golang.org/x/net/html has quadratic parsing complexity when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.
Remediation
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
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-2025-206856

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 no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. 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

The html.Parse function in golang.org/x/net/html has quadratic parsing complexity when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.

What

The html.Parse function in golang.org/x/net/html has quadratic parsing complexity when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

The html.Parse function in golang.org/x/net/html has quadratic parsing complexity when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Uncontrolled Resource Consumption → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-400 ↗

CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Common Vulnerability Scoring System 3.1: 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.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.ALowAvailability impact: A successful attack can cause a limited loss.
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.
NetworkUnauthenticatedDenial of serviceCWE-400
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-1618Splunk Splunk Enterprise: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise ausnutzen, um Sicherheitsvorkehrungen zu umgehen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260211Security Bulletin 11 Feb 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 11 Feb 2026, published on 11 February 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0641Multiples vulnérabilités dans les produits IBM

d?id=CVE-2025-36387 Référence CVE CVE-2025-36407 https://www.cve.org/CVERecord?id=CVE-2025-36407 Référence CVE CVE-2025-36424 https://www.cve.org/CVERecord?id=CVE-2025-36424 Référence CVE CVE-2025-36425 https://www.cve.org/CVERecord?id=CVE-2025-36425 Référence CVE CVE-2025-36427 https://www.cve.org/CVERecord?id=CVE-2025-36427 Référence CVE CVE-2025-36428 https://www.cve.org/CVERecord?id=CVE-2025-36428 Référence CVE CVE-2025-36442 https://www.cve.org/CVERecord?id=CVE-2025-36442 Référence CVE CVE-2025-38351 https://www.cve.org/CVERecord?id=CVE-2025-38351 Référence CVE CVE-2025-39761 https://www.cve.org/CVERecord?id=CVE-2025-39761 Référence CVE CVE-2025-47911 https://www.cve.org/CVERecord?id=CVE-2025-47911 Référence CVE CVE-2025-47914 https://www.cve.org/CVERecord?id=CVE-2025-47914 Référence CVE CVE-2025-48924 https://www.cve.org/CVERecord?id=CVE-2025-48924 Référence CVE CVE-2025-53057 https://www.cve.org/CVERecord?id=CVE-2025-53057 Référence CVE CVE-2025-53066 https://www.cve.org/CVERecord?id=CVE-2025-53066 Référence CVE CVE-2025-53864 https://www.cve.org/CVERecord?id=CVE-2025-53864 Référence CVE CVE-2025-54410 https://www.cve.org/CVERecord?id=CVE-2025-54410 Référence CVE CVE-2025-55163 https://www.cve.org/CVERecord?id=CVE-2025-55163 Référence CVE CVE-2025-58056 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0627Multiples vulnérabilités dans les produits Splunk

/CVERecord?id=CVE-2025-4435 Référence CVE CVE-2025-4516 https://www.cve.org/CVERecord?id=CVE-2025-4516 Référence CVE CVE-2025-4517 https://www.cve.org/CVERecord?id=CVE-2025-4517 Référence CVE CVE-2025-4565 https://www.cve.org/CVERecord?id=CVE-2025-4565 Référence CVE CVE-2025-46394 https://www.cve.org/CVERecord?id=CVE-2025-46394 Référence CVE CVE-2025-4674 https://www.cve.org/CVERecord?id=CVE-2025-4674 Référence CVE CVE-2025-46762 https://www.cve.org/CVERecord?id=CVE-2025-46762 Référence CVE CVE-2025-47273 https://www.cve.org/CVERecord?id=CVE-2025-47273 Référence CVE CVE-2025-47907 https://www.cve.org/CVERecord?id=CVE-2025-47907 Référence CVE CVE-2025-47911 https://www.cve.org/CVERecord?id=CVE-2025-47911 Référence CVE CVE-2025-47913 https://www.cve.org/CVERecord?id=CVE-2025-47913 Référence CVE CVE-2025-48924 https://www.cve.org/CVERecord?id=CVE-2025-48924 Référence CVE CVE-2025-49146 https://www.cve.org/CVERecord?id=CVE-2025-49146 Référence CVE CVE-2025-49844 https://www.cve.org/CVERecord?id=CVE-2025-49844 Référence CVE CVE-2025-50059 https://www.cve.org/CVERecord?id=CVE-2025-50059 Référence CVE CVE-2025-50106 https://www.cve.org/CVERecord?id=CVE-2025-50106 Référence CVE CVE-2025-50181 https://www.cve.org/CVERecord?id=CVE-2025-50181 Référence CVE CVE-2025-52565 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0218Multiples vulnérabilités dans les produits VMware

ERecord?id=CVE-2025-45768 Référence CVE CVE-2025-4598 https://www.cve.org/CVERecord?id=CVE-2025-4598 Référence CVE CVE-2025-46394 https://www.cve.org/CVERecord?id=CVE-2025-46394 Référence CVE CVE-2025-4673 https://www.cve.org/CVERecord?id=CVE-2025-4673 Référence CVE CVE-2025-4674 https://www.cve.org/CVERecord?id=CVE-2025-4674 Référence CVE CVE-2025-47273 https://www.cve.org/CVERecord?id=CVE-2025-47273 Référence CVE CVE-2025-47906 https://www.cve.org/CVERecord?id=CVE-2025-47906 Référence CVE CVE-2025-47907 https://www.cve.org/CVERecord?id=CVE-2025-47907 Référence CVE CVE-2025-47910 https://www.cve.org/CVERecord?id=CVE-2025-47910 Référence CVE CVE-2025-47911 https://www.cve.org/CVERecord?id=CVE-2025-47911 Référence CVE CVE-2025-47912 https://www.cve.org/CVERecord?id=CVE-2025-47912 Référence CVE CVE-2025-47913 https://www.cve.org/CVERecord?id=CVE-2025-47913 Référence CVE CVE-2025-47914 https://www.cve.org/CVERecord?id=CVE-2025-47914 Référence CVE CVE-2025-4802 https://www.cve.org/CVERecord?id=CVE-2025-4802 Référence CVE CVE-2025-48060 https://www.cve.org/CVERecord?id=CVE-2025-48060 Référence CVE CVE-2025-48734 https://www.cve.org/CVERecord?id=CVE-2025-48734 Référence CVE CVE-2025-48924 https://www.cve.org/CVERecord?id=CVE-2025-48924 Référence CVE CVE-2025-4947 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-004221Goのhtmlにおける不特定の脆弱性

golang.org/x/net/html の html.Parse 関数は、特定の入力を処理する際に二次の解析計算量を持ちます。攻撃者が特別に細工されたHTMLコンテンツを提供すると、サービス拒否（DoS）を引き起こす可能性があります。

Official advisory ↗
03

Patch and workaround

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.
Fix availability varies by product
Affected
Fixed
Action
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 5 Feb 2026 · Last source change 12 Feb 2026, 15:23 UTC · CWE-400 · Uncontrolled Resource Consumption

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-206856
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    < 0.45.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    < 0.45.0 · Fixed: Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2025-206856↗Red Hat Product Security security advisory↗CVE authority or vendor reference↗Vendor advisory↗Official CVE record (CNA and ADP data)↗NVD record↗
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.
Free version - for non-commercial use only.CVE-2025-47911 · cve.blacktree.nl