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TI-2026-53818 Aliases CVE-2026-77063GHSA-qvfw-j98x-7q72

multer vulnerable to file size limit bypass via async fileFilter race condition

Priority LOW 17CWE-362Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Partial Red Hat: 9 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

multer is a middleware for handling multipart/form-data in Node.js. When an application uses an asynchronous fileFilter together with the fileSize limit, a race condition in multer's file stream handling can allow a file that exceeds the configured size limit to bypass the size-limit rejection. All versions before 2.3.0 are affected. The impact is limited because the underlying multipart parser still truncates the stream at the size limit, so this is a bypass of the limit rejection rather than uncontrolled resource consumption. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00233 14th percentileScored 2026-11-07
Fix Partial multer (multer): 2.3.0multer (npm): 2.3.0Red Hat: 9 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
expressjsmulterbefore 2.3.02.3.0Patch availableCNA
—multer (npm)before 2.3.02.3.0Patch availableGHSA-qvfw-j98x-7q72
  • multer Vendorexpressjs Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA
  • multer (npm) Vendor— Affected before 2.3.0 Fixed in 2.3.0 Patch available GHSA-qvfw-j98x-7q72

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:expressjs:multer:*:*:*:*:*:node.js:*:*before 2.3.0Vulnerableexpressjs
  • cpe:2.3:a:expressjs:multer:*:*:*:*:*:node.js:*:* Versions before 2.3.0 Vulnerable ·expressjs

Remediation

  • Fix · CNA multer (multer) Fixed in 2.3.0
  • Fix · GHSA-qvfw-j98x-7q72 multer (npm) Fixed in 2.3.0 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    multer 2.3.0

    4 records Highest priority Priority LOW 4 LOW

    Other records, highest priority first

    • TI-2026-56780 multer vulnerable to Denial of Service via oversized array index in field namesPriority LOW 39
    • TI-2026-53831 multer vulnerable to Denial of Service via crafted multipart field namesPriority LOW 39
    • TI-2026-53816 multer vulnerable to Denial of Service via file descriptor leak on aborted uploadsPriority LOW 39
    Show all 4 records →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Logging Subsystem for Red Hat OpenShiftAffectedNo fix yet: Fix deferred
Red Hat 3scale API Management Platform 2AffectedNo fix yet: Fix deferred
Red Hat Developer Hub 1AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Trusted Profile AnalyzerAffectedNo fix yet: Fix deferred
Self-service automation portal 2AffectedNo fix yet: Fix deferred
Not affected: 1 product
  • Red Hat Hardened Images

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-77063
  2. 2026-10-03 Alias added: GHSA-qvfw-j98x-7q72
  3. 2026-10-27 Affected versions changed · Red Hat

References

Advisory 3

Other 3

  • TI-2026-03033 Multer vulnerable to Denial of Service via uncontrolled recursion CVSS 4.0HIGH 8.7
  • TI-2026-02853 Multer vulnerable to Denial of Service via incomplete cleanup CVSS 4.0HIGH 8.7
  • TI-2026-01995 Multer vulnerable to Denial of Service via resource exhaustion CVSS 4.0HIGH 8.7
  • TI-2026-56780 multer vulnerable to Denial of Service via oversized array index in field names CVSS 3.1HIGH 7.5
  • TI-2026-53831 multer vulnerable to Denial of Service via crafted multipart field names CVSS 3.1HIGH 7.5
  • TI-2026-53816 multer vulnerable to Denial of Service via file descriptor leak on aborted uploads CVSS 3.1HIGH 7.5
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences