CVE-2026-77078

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 28, 2026

Last Modified

September 2, 2026

Advisory Details (2)

Auto-updated Aug 28, 2026
Patch available. Sources: github.
github Patch Available

multer vulnerable to Denial of Service via crafted multipart field names · Advisory · expressjs/multer · GitHub

https://github.com/expressjs/multer/security/advisories/GHSA-wc9g-mqfw-jrwm
generic

Security Advisories | OpenJS Foundation CVE Numbering Authority

https://cna.openjsf.org/security-advisories.html

Vendor Advisories for CVE-2026-77078(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
multer—2.3.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 05:50 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:50 UTCEG score recompute
  4. 2026-09-16 21:51 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 10:50 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 12:48 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-13 16:48 UTCEG score recompute
  11. 2026-09-12 18:48 UTCEG score recompute
  12. 2026-09-12 15:02 UTCEPSS rescore
  13. 2026-09-11 20:48 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 09:46 UTCEG score recompute
  16. 2026-09-10 11:45 UTCEG score recompute
  17. 2026-09-10 09:35 UTCEPSS rescore
  18. 2026-09-09 00:26 UTCEG score recompute
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-07 16:15 UTCEG score recompute
  21. 2026-09-06 18:12 UTCEG score recompute
  22. 2026-09-06 13:48 UTCEPSS rescore
  23. 2026-09-05 20:11 UTCEG score recompute
  24. 2026-09-04 22:11 UTCEG score recompute
  25. 2026-09-04 11:06 UTCEG score recompute
Show 18 more
  1. 2026-09-04 05:07 UTCEPSS rescore
  2. 2026-09-02 15:01 UTCEG score recompute
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 17:32 UTCEG score recompute
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-09-01 06:31 UTCEG score recompute
  7. 2026-09-01 04:40 UTCEPSS rescore
  8. 2026-09-01 04:40 UTCEPSS rescore
  9. 2026-08-31 19:31 UTCEG score recompute
  10. 2026-08-31 18:56 UTCEG score recompute
  11. 2026-08-31 05:45 UTCEG score recompute
  12. 2026-08-30 19:18 UTCEPSS rescore
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 07:45 UTCEG score recompute
  15. 2026-08-30 01:22 UTCEPSS rescore
  16. 2026-08-28 22:44 UTCEG score recompute
  17. 2026-08-28 22:02 UTCEG score recompute
  18. 2026-08-28 21:59 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77078?
CVE-2026-77078 is a high vulnerability published on August 28, 2026. multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to…
When was CVE-2026-77078 disclosed?
CVE-2026-77078 was first published in the National Vulnerability Database on August 28, 2026, with the most recent update on September 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77078 actively exploited?
CVE-2026-77078 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.1% of all scored CVEs.
What is the CVSS score of CVE-2026-77078?
CVE-2026-77078 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-77078?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77078, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-77078

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