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 0.35% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-77037High confidence
multer vulnerable to Denial of Service via file descriptor leak on aborted uploads
multer · multer
Official source article: GitHub GHSA-QFVM-CV95-JQJF ↗. Check the applicable product and release in the original source.
7.5HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 27 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
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
- Confirm that the asset runs multer multer 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.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 27 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 27 affected or under-investigation product states without a fixed product state in the same current advisory
Open-source package ranges1 source-attributed range
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 package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| npmmulter | = 2.2.0 | 2.3.0 | GitHub advisory ↗upstream repository advisory · 8 Sep 2026 |
Direct vendor intelligence
1 currentAuthoritative 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.
CVE-2026-77037 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitymulter: Multer: Denial of Service via file descriptor leak on aborted uploads
The vendor explicitly identifies these products as affected by this CVE.
- openshift-logging/vector-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
- rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend as a component of Red Hat Developer Hub
- rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend as a component of Red Hat Developer Hub
- rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub
- firefox as a component of Red Hat Enterprise Linux 10
- firefox.src as a component of Red Hat Enterprise Linux 10
- thunderbird as a component of Red Hat Enterprise Linux 10
- thunderbird.src as a component of Red Hat Enterprise Linux 10
- firefox as a component of Red Hat Enterprise Linux 7
- firefox.src as a component of Red Hat Enterprise Linux 7
- thunderbird as a component of Red Hat Enterprise Linux 8
- thunderbird.src as a component of Red Hat Enterprise Linux 8
- Summary
- A flaw was found in multer, a Node.js middleware for handling multipart/form-data. A remote attacker can exploit a file descriptor leak by sending repeated aborted or malformed multipart uploads. This can exhaust system resources, leading to a denial of service (DoS) for the affected application.
- Remediation
- Upgrade to multer 2.3.0 or later, which properly closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed.
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 27 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
What
multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
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
multer is a middleware for handling multipart/form-data in Node.js. In version 2.2.0, when a disk-backed upload is aborted or truncated before the write stream finishes, multer's disk storage engine removes the visible file but does not close the underlying write file descriptor, leaving a deleted but still open descriptor. A remote attacker able to reach an upload route using the built-in disk storage can send repeated aborted or malformed multipart uploads, each one leaking a file descriptor and retaining disk blocks until the process exits, which can exhaust resources and cause a denial of service. The issue is fixed in multer 2.3.0, which closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed. Upgrade to multer 2.3.0 to remediate.
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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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:HCommon 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.AHighAvailability impact: A successful attack can cause a major 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.
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
- openshift-logging/vector-rhel9 as a component of Logging Subsystem for Red Hat OpenShift
- rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend as a component of Red Hat Developer Hub
- rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend as a component of Red Hat Developer Hub
- rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub
- firefox as a component of Red Hat Enterprise Linux 10
- firefox.src as a component of Red Hat Enterprise Linux 10
- thunderbird as a component of Red Hat Enterprise Linux 10
- thunderbird.src as a component of Red Hat Enterprise Linux 10
- firefox as a component of Red Hat Enterprise Linux 7
- firefox.src as a component of Red Hat Enterprise Linux 7
- thunderbird as a component of Red Hat Enterprise Linux 8
- thunderbird.src as a component of Red Hat Enterprise Linux 8
- fdo-admin-cli as a component of Red Hat Enterprise Linux 9
- fdo-client as a component of Red Hat Enterprise Linux 9
- fdo-init as a component of Red Hat Enterprise Linux 9
- fdo-manufacturing-server as a component of Red Hat Enterprise Linux 9
- fdo-owner-cli as a component of Red Hat Enterprise Linux 9
- fdo-owner-onboarding-server as a component of Red Hat Enterprise Linux 9
- fdo-rendezvous-server as a component of Red Hat Enterprise Linux 9
- firefox as a component of Red Hat Enterprise Linux 9
- firefox-x11 as a component of Red Hat Enterprise Linux 9
- firefox.src as a component of Red Hat Enterprise Linux 9
- thunderbird as a component of Red Hat Enterprise Linux 9
- thunderbird.src as a component of Red Hat Enterprise Linux 9
- rhtpa/rhtpa-trustification-service-rhel9 as a component of Red Hat Trusted Profile Analyzer
- ansible-automation-platform/automation-portal as a component of Self-service automation portal 2
- ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2
- Fixed
- multer: 2.3.0
- 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
- Upgrade to multer 2.3.0 or later, which properly closes the destination write stream on abnormal source termination and defers cleanup until the stream has closed.
Official vendor articles1 stored document
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- multer vulnerable to Denial of Service via file descriptor leak on aborted uploads · Advisory · expressjs/multer · GitHub →Original publisher ↗Searchable text snapshot · Captured 27 Sep 2026expressjs / multer Public Uh oh! There was an error while loading. Please reload this page . Notifications You must be signed in to change notification settings Fork 1.1k Star 12.1k Code Issues 148 Pull requests 16 Discussions Actions Projects Wiki Security and quality 14 Insights Additional navigatio
04
Evidence and provenance
Published 28 Aug 2026 · Last source change 31 Aug 2026, 18:41 UTC · CWE-400 · Uncontrolled Resource Consumption
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-29
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-67928
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
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Red Hat Product Security ↗
- Before
- openshift-logging/vector-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; 3scale-amp2/system-rhel8 as a component of Red Hat 3scale API Management Platform 2; rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend as a component of Red Hat Developer Hub; rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend as a component of Red Hat Developer Hub; rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub; firefox as a component of Red Hat Enterprise Linux 10; firefox.src as a component of Red Hat Enterprise Linux 10; thunderbird as a component of Red Hat Enterprise Linux 10; thunderbird.src as a component of Red Hat Enterprise Linux 10; firefox as a component of Red Hat Enterprise Linux 7; firefox.src as a component of Red Hat Enterprise Linux 7; thunderbird as a component of Red Hat Enterprise Linux 8; thunderbird.src as a component of Red Hat Enterprise Linux 8; fdo-admin-cli as a component of Red Hat Enterprise Linux 9; fdo-client as a component of Red Hat Enterprise Linux 9; fdo-init as a component of Red Hat Enterprise Linux 9; fdo-manufacturing-server as a component of Red Hat Enterprise Linux 9; fdo-owner-cli as a component of Red Hat Enterprise Linux 9; fdo-owner-onboarding-server as a component of Red Hat Enterprise Linux 9; fdo-rendezvous-server as a component of Red Hat Enterprise Linux 9; firefox as a component of Red Hat Enterprise Linux 9; firefox-x11 as a component of Red Hat Enterprise Linux 9; firefox.src as a component of Red Hat Enterprise Linux 9; thunderbird as a component of Red Hat Enterprise Linux 9; thunderbird.src as a component of Red Hat Enterprise Linux 9; rhtpa/rhtpa-trustification-service-rhel9 as a component of Red Hat Trusted Profile Analyzer; ansible-automation-platform/automation-portal as a component of Self-service automation portal 2; ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2
- After
- openshift-logging/vector-rhel9 as a component of Logging Subsystem for Red Hat OpenShift; rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend as a component of Red Hat Developer Hub; rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend as a component of Red Hat Developer Hub; rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub; firefox as a component of Red Hat Enterprise Linux 10; firefox.src as a component of Red Hat Enterprise Linux 10; thunderbird as a component of Red Hat Enterprise Linux 10; thunderbird.src as a component of Red Hat Enterprise Linux 10; firefox as a component of Red Hat Enterprise Linux 7; firefox.src as a component of Red Hat Enterprise Linux 7; thunderbird as a component of Red Hat Enterprise Linux 8; thunderbird.src as a component of Red Hat Enterprise Linux 8; fdo-admin-cli as a component of Red Hat Enterprise Linux 9; fdo-client as a component of Red Hat Enterprise Linux 9; fdo-init as a component of Red Hat Enterprise Linux 9; fdo-manufacturing-server as a component of Red Hat Enterprise Linux 9; fdo-owner-cli as a component of Red Hat Enterprise Linux 9; fdo-owner-onboarding-server as a component of Red Hat Enterprise Linux 9; fdo-rendezvous-server as a component of Red Hat Enterprise Linux 9; firefox as a component of Red Hat Enterprise Linux 9; firefox-x11 as a component of Red Hat Enterprise Linux 9; firefox.src as a component of Red Hat Enterprise Linux 9; thunderbird as a component of Red Hat Enterprise Linux 9; thunderbird.src as a component of Red Hat Enterprise Linux 9; rhtpa/rhtpa-trustification-service-rhel9 as a component of Red Hat Trusted Profile Analyzer; ansible-automation-platform/automation-portal as a component of Self-service automation portal 2; ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: cna.openjsf.org/security-advisories.html; added vendor advisory: github.com/GHSA-qfvm-cv95-jqjf.github.com ↗
- Before
- remediation: github.com/GHSA-qfvm-cv95-jqjf
- After
- remediation: github.com/GHSA-qfvm-cv95-jqjf · vendor advisory: cna.openjsf.org/security-advisories.html · vendor advisory: github.com/GHSA-qfvm-cv95-jqjf
- ENISA EUVD mappingEUVD-2026-67928 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-67928"}
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- 2.2.0 < 2.3.0 · Fixed: 2.3.0
- After
- multer: 2.2.0 < 2.3.0 · Fixed: multer: 2.3.0
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
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.