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HIGH

CVE-2026-77078

CVSS v3

7.5

HIGH

EPSS Score

0.5 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • multernpmall versions · fixed in 2.3.0

Vendor advisories

  • CVE-2026-77078 Red Hat Product Security3 products fixed

    multer: Multer: Denial of Service via crafted multipart field names

  • RHSA-2026:79088 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat Developer Hub 1.10.5 release.

  • RHSA-2026:76788 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: Red Hat Developer Hub 1.10.5 Plugin Catalog GA plugins release.

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-08-28
Last Modified
2026-08-28

Frequently asked questions

What is CVE-2026-77078?

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.

Is CVE-2026-77078 actively exploited?

Active exploitation of CVE-2026-77078 has not been confirmed. Its EPSS score was 0.5% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-77078?

CVE-2026-77078 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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