CVE-2026-109924

undici is an HTTP client library for Node.js. In versions 6.5.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its EventSource client can be driven to exhaust process memory by a malicious or compromised Server-Sent Events peer. By sending millions of tiny completed data fields with no blank event separator, or a single unfinished line split across many chunks, the parser retains a growing amount of per-field and per-chunk state that the byte-based maxEventSize and maxResponseSize limits do not bound, and because maxResponseSize is enforced on the compressed body before decompression, a small compressed response can expand into enough retained memory to terminate the process. An application only needs to maintain an EventSource connection to an untrusted peer, which controls only the response, and availability is the only impact. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which bound the retained parser state independently of the byte limits, and users should upgrade to one of those versions or later. There is no workaround.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*

History

19 Oct 2026, 20:45

Type Values Removed Values Added
CPE cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*
References () https://cna.openjsf.org/security-advisories.html - () https://cna.openjsf.org/security-advisories.html - Vendor Advisory
References () https://github.com/nodejs/undici/security/advisories/GHSA-4qv8-2p9j-2685 - () https://github.com/nodejs/undici/security/advisories/GHSA-4qv8-2p9j-2685 - Vendor Advisory
First Time Nodejs
Nodejs undici

15 Oct 2026, 19:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-10-15 19:17

Updated : 2026-10-19 20:45


NVD link : CVE-2026-109924

Mitre link : CVE-2026-109924

CVE.ORG link : CVE-2026-109924


JSON object : View

Products Affected

nodejs

  • undici
CWE
CWE-770

Allocation of Resources Without Limits or Throttling