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Full vulnerability report · 2026
CVE-2026-88932High confidence

multer vulnerable to Denial of Service via orphaned disk writes on aborted uploads

multer · multer

Official source article: GitHub GHSA-3PPH-FPJX-JG34 ↗. Check the applicable product and release in the original source.

5.3MediumCVSS 3.1
Recommended action
Scheduled

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

Patch available
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 0.53% 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 multer multer 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.

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
npmmulter>= 2.2.0, < 2.4.02.4.0GitHub advisory ↗upstream repository advisory · 28 Sep 2026
npmmulterSEMVER: introduced 2.2.0; fixed 2.4.02.4.0OSV record ↗aggregator derived · 28 Sep 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-2026-88932 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitymulter: multer: Denial of Service via orphaned disk writes on aborted uploads
2 known affected

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

  • rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub
  • ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2
Summary
A flaw was found in multer, a Node.js middleware for handling multipart/form-data uploads. When a request using disk storage is aborted during an upload, file writes that complete after multer's cleanup process are not removed. This can leave orphaned files on disk. A remote unauthenticated attacker can repeatedly initiate and abort uploads to accumulate these orphaned files, which can exhaust disk space and lead to a denial of service.
Remediation
For more about Ansible plugins for Red Hat Developer Hub, see References links
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-2026-77332

No EUVD known-exploited evidence

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

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
5.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

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

Patch available
01

What, why and how

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

What

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

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 Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

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.

ENISA EUVD · EUVD-2026-77332Official EUVD mapping

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

Official EUVD record ↗
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.
Patch available
Affected
Fixed
Action
For more about Ansible plugins for Red Hat Developer Hub, see References links
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 Sept 2026 · Last source change 14 Sept 2026, 10:29 UTC · CWE-400 · Uncontrolled Resource Consumption

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 2026-09-14
European sourceENISA EUVD · EUVD-2026-77332
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

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
    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; ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2 · Fixed: registry.redhat.io/ansible-automation-platform/automation-portal@sha256:2659ae04974d930322789112efc9181bc7cf3990999a204eba45aec0639f0c3d_amd64 as a component of Red Hat Ansible Automation Platform 2.1; registry.redhat.io/ansible-automation-platform/automation-portal@sha256:ca5c8160a6cb0fa122c3cc91852325af72b9713db1c2683b68e91433b762e604_amd64 as a component of Red Hat Ansible Automation Platform 2.2
    After
    rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub; ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2 · Fixed: registry.redhat.io/ansible-automation-platform/automation-portal@sha256:2659ae04974d930322789112efc9181bc7cf3990999a204eba45aec0639f0c3d_amd64 as a component of Red Hat Ansible Automation Platform 2.1; registry.redhat.io/ansible-automation-platform/automation-portal@sha256:ca5c8160a6cb0fa122c3cc91852325af72b9713db1c2683b68e91433b762e604_amd64 as a component of Red Hat Ansible Automation Platform 2.2; registry.redhat.io/rhdh/red-hat-developer-hub-backstage-plugin-lightspeed-backend@sha256:55b8b4e43f9dd474dee53d824591695012994daec86efee4dc08612b12425a46_amd64 as a component of Red Hat Developer Hub 1.10; registry.redhat.io/rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend@sha256:c6a5e6d9c8f3ab900c2b29848273540f4a3e97d351faa338a66da46c0b59d04f_amd64 as a component of Red Hat Developer Hub 1.10
    Red Hat Product Security ↗
  2. Vendor guidanceAuthoritative vendor guidance changed from remediation: access.redhat.com/CVE-2026-88932 to remediation: access.redhat.com/CVE-2026-88932.
    Before
    remediation: access.redhat.com/CVE-2026-88932
    After
    remediation: access.redhat.com/CVE-2026-88932
    Red Hat Product Security ↗
  3. Remediation statusRemediation status changed from Mitigation available to Patch available.
    Before
    Mitigation available
    After
    Patch available
    Red Hat Product Security ↗
  4. Affected versionsThe structured affected or fixed version information changed.
    Before
    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; 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
    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; ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2 · Fixed: registry.redhat.io/ansible-automation-platform/automation-portal@sha256:2659ae04974d930322789112efc9181bc7cf3990999a204eba45aec0639f0c3d_amd64 as a component of Red Hat Ansible Automation Platform 2.1; registry.redhat.io/ansible-automation-platform/automation-portal@sha256:ca5c8160a6cb0fa122c3cc91852325af72b9713db1c2683b68e91433b762e604_amd64 as a component of Red Hat Ansible Automation Platform 2.2
    Red Hat Product Security ↗
  5. Vendor guidanceAuthoritative vendor guidance changed from remediation: access.redhat.com/CVE-2026-88932 to remediation: access.redhat.com/CVE-2026-88932.
    Before
    remediation: access.redhat.com/CVE-2026-88932
    After
    remediation: access.redhat.com/CVE-2026-88932
    Red Hat Product Security ↗
  6. Affected versionsThe structured affected or fixed version information changed.
    Before
    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; 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
    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; 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
    Red Hat Product Security ↗
  7. Vendor guidanceAuthoritative vendor guidance changed from remediation: access.redhat.com/CVE-2026-88932 to remediation: access.redhat.com/CVE-2026-88932.
    Before
    remediation: access.redhat.com/CVE-2026-88932
    After
    remediation: access.redhat.com/CVE-2026-88932
    Red Hat Product Security ↗
  8. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Red Hat Product Security ↗
  9. ENISA EUVD mappingEUVD-2026-77332 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-77332"}
    ENISA EUVD ↗
  10. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-77332↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference · GitHub GHSA-3PPH-FPJX-JG34↗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-2026-88932 · cve.blacktree.nl