{"id":"CVE-2026-88878","title":"Traefik is an HTTP reverse proxy and load balancer","summary":"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 defau…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-770"],"vendor":"traefik","product":"traefik","affected":["traefik >= 2.8.2, < 2.11.56","traefik >= 3.0.0, < 3.7.12"],"patched":["traefik 3.7.12"],"published":"2026-09-10","updated":"2026-09-14","sourceUpdated":"2026-09-14T19:58:08.727","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-88878","references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/traefik-2.8.2-through-3.6-http-3-timeout-bypass","label":"disclosure@vulncheck.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88878.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-88878"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2531451"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-88878"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88878"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00304,"epssPercentile":0.23391,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-10T14:22:22.467169Z"},"scores":{"nvd":5.3,"vendor":7.5,"cna":5.3},"ingestedAt":"2026-09-10T13:50:37.334Z","slug":"CVE-2026-88878","body":"## Overview\n\nTraefik 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.\n\n## Affected\n\n- `traefik >= 2.8.2, < 2.11.56`\n- `traefik >= 3.0.0, < 3.7.12`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `traefik 3.7.12`\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat OpenShift Dev Spaces · no fix planned: Red Hat OpenShift Dev Spaces · updated 2026-09-12 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88878.json)","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}