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.
References
| Link | Resource |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Vendor Advisory |
| https://github.com/nodejs/undici/security/advisories/GHSA-4qv8-2p9j-2685 | Vendor Advisory |
Configurations
Configuration 1 (hide)
|
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 - Vendor Advisory | |
| References | () 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
