← back
CVE-2026-6733lowCWE-367

undici vulnerable to HTTP response queue poisoning via keep-alive socket reuse

8Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 3.7epss 0.2%
exploitation probability
0.2%top 87% of all CVEs
observed exploitation
nono source reports it
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/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
undici · undici