undici vulnerable to HTTP response queue poisoning via keep-alive socket reuse
cve-program · CVE-2026-6733
PublishedImpact: 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.
Read the publisher's advisoryeuvd · EUVD-2026-37769
PublishedImpact: 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.
Read the publisher's advisorynvd · CVE-2026-6733
PublishedImpact: 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.
Read the publisher's advisoryosv · GHSA-35p6-xmwp-9g52
Published## 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 v6.27.0, v7.28.0 or v8.5.0. ## Workarounds Disable keep-alive connection reuse by setting `keepAliveTimeout: 0` on the Client or Pool.
Read the publisher's advisoryAffected versions, risk and source history
Related advisories and sources
Publishers link these advisories through the identifiers shown below. A shared identifier or date alone does not tell you whether your software is affected or whether the advisories describe the same cause.
CVE-2026-6733 · CVE overview and exploitation status
cve-program · CVE-2026-6733
- https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52
- https://hackerone.com/reports/3582376
- https://cna.openjsf.org/security-advisories.html
euvd · EUVD-2026-37769
- https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52
- https://hackerone.com/reports/3582376
- https://cna.openjsf.org/security-advisories.html
nvd · CVE-2026-6733
- https://cna.openjsf.org/security-advisories.html
- https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52
- https://hackerone.com/reports/3582376
osv · GHSA-35p6-xmwp-9g52
- https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52
- https://nvd.nist.gov/vuln/detail/CVE-2026-6733
- https://github.com/nodejs/undici/commit/6ea54ef8c4051e95bb68c89d4a5c9274fe6fbb4b
- https://hackerone.com/reports/3582376
- https://cna.openjsf.org/security-advisories.html
- https://github.com/nodejs/undici
- https://github.com/nodejs/undici/releases/tag/v6.27.0
- https://github.com/nodejs/undici/releases/tag/v7.28.0
- https://github.com/nodejs/undici/releases/tag/v8.5.0