CVE-2026-6733
Impact: Undici's HTTP/1.1 client is vulnerable to response queue poisoning on reused keep-alive sockets.
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
Description
Impact: Undici's HTTP/1.1 client is vulnerable to response queue poisoning on reused keep-alive sockets. An attacker-controlled upstream server can inject an unsolicited HTTP/1.1 response onto an idle socket after a request completes. When the client dispatches the next request on that socket, it associates the injected response with the new request, causing responses to be delivered to the wrong requests. This requires an attacker-controlled or compromised upstream HTTP/1.1 server and keep-alive connection reuse. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: Disable keep-alive connection reuse by setting keepAliveTimeout: 0 on the Client or Pool.
- CVSS 3.1
- 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.22% probability · 13th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- nodejs/undici
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
References
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52Mitigation, Vendor Advisory
- https://hackerone.com/reports/3582376Issue Tracking
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.