{"id":"CVE-2026-88878","state":"PUBLISHED","title":"Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass","description":"Traefik is an HTTP reverse proxy and load balancer. In versions >= v2.8.2 through <= v2.11.55 and >= v3.0.0 through <= v3.7.11, the entryPoints.<name>.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.","publishedAt":"2026-09-10T13:05:30.181Z","updatedAt":"2026-10-08T15:25:58.415Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["traefik traefik"],"affected":[{"vendor":"traefik","product":"traefik","packageURL":"pkg:golang/github.com/traefik/traefik/v2","defaultStatus":"unaffected","versions":[{"version":"2.8.2","status":"affected","lessThanOrEqual":"3.7.13","versionType":"semver"}]},{"vendor":"traefik","product":"traefik","packageURL":"pkg:golang/github.com/traefik/traefik/v3","defaultStatus":"unaffected","versions":[{"version":"3.0.0","status":"affected","lessThanOrEqual":"3.7.13","versionType":"semver"}]}],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c","https://www.vulncheck.com/advisories/traefik-2.8.2-through-3.6-http-3-timeout-bypass"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/88xxx/CVE-2026-88878.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-88878","state":"PUBLISHED","datePublished":"2026-09-10T13:05:30.181Z","dateUpdated":"2026-10-08T15:25:58.415Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-10T11:24:26.196Z"},"containers":{"cna":{"title":"Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass","descriptions":[{"lang":"en","value":"Traefik is an HTTP reverse proxy and load balancer. 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