{"id":"CVE-2026-88878","summary":"Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass","details":"Traefik is an HTTP reverse proxy and load balancer. In versions \u003e= v2.8.2 through \u003c= v2.11.55 and \u003e= v3.0.0 through \u003c= v3.7.11, the entryPoints.\u003cname\u003e.transport.respondingTimeouts settings — notably readTimeout, which is enabled by default at 60s — are not applied to the HTTP/3 request path. readTimeout is enforced as a deadline on the underlying TCP connection, which cannot be applied to a QUIC stream, and Traefik's HTTP/3 server is constructed without any timeout. As a result, on entry points with HTTP/3 enabled, an unauthenticated remote client that trickles request body bytes can hold a request open indefinitely and, with it, one upstream connection per request, exhausting bounded backend connection pools and causing denial of service. The issue was introduced in v2.8.2 when a quic-go API change removed the embedded http.Server that carried these timeouts. Fixed in v2.11.56 and v3.7.12.","aliases":["CVE-2026-88012","GHSA-7ghq-v6jf-g56c","GO-2026-6454"],"modified":"2026-09-17T17:40:35.776639750Z","published":"2026-09-10T13:05:30.181Z","database_specific":{"cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88878.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88878.json"},{"type":"ADVISORY","url":"https://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88878"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/traefik-2.8.2-through-3.6-http-3-timeout-bypass"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/traefik/traefik","events":[{"introduced":"23c26d64eeb72eaecaecedc31ca740e83304fde2"},{"fixed":"d87731461f0c7beb6fdbcc5a5655a44ce56e537a"},{"introduced":"d99d2f95e66a28ee8180634dc80fdf13ba68c62a"},{"fixed":"e8f398ee30ca5643158ea9094b701b8eae9849e5"}],"database_specific":{"source":"CPE_RANGE","cpe":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"2.8.2"},{"fixed":"2.11.56"},{"introduced":"3.0.0"},{"fixed":"3.7.12"}]}}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-88878.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}