CVE-2026-88878

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{"bugzilla": {"description": "github.com/traefik/traefik: Traefik: Denial of Service via HTTP/3 timeout bypass", "id": "2531451", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2531451"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-770", "details": ["A flaw was found in Traefik, an HTTP reverse proxy and load balancer. When HTTP/3 is enabled, an unauthenticated remote client can exploit a timeout bypass vulnerability by trickling request body bytes. This allows the client to hold a request open indefinitely, exhausting backend connection pools and leading to a denial of service (DoS) for legitimate users."], "mitigation": {"lang": "en:us", "value": "Disable HTTP/3 on all Traefik entry points by removing the entryPoints.<name>.http3 configuration or setting enabled: false. Alternatively, enforce strict request body timeouts and connection limits at an upstream load balancer or network gateway."}, "name": "CVE-2026-88878", "public_date": "2026-09-10T13:05:30Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-88878\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-88878\nhttps://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c\nhttps://www.vulncheck.com/advisories/traefik-2.8.2-through-3.6-http-3-timeout-bypass"], "statement": "A flaw was found in Traefik's HTTP/3 implementation (v2.8.2 through v2.11.55 and v3.0.0 through v3.7.11) where respondingTimeouts settings, specifically readTimeout, are not applied to QUIC streams. On entry points with HTTP/3 enabled, an unauthenticated remote client can trickle request body bytes to keep HTTP/3 streams open indefinitely without triggering timeout deadlines. In environments utilizing affected Traefik components, this allows attackers to exhaust bounded upstream backend connection pools, resulting in a denial of service for legitimate users.", "threat_severity": "Important"}

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