What’s Vulnerable › Vulnerabilities

CVE-2026-88012: Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-10 · updated 2026-09-14
• Weakness: CWE-770

Description

Traefik is an open source HTTP reverse proxy and load balancer. From 2.8.2 until 2.11.56 and 3.7.12, HTTP/3 entrypoints do not apply entryPoints..transport.respondingTimeouts.readTimeout because the timeout is enforced on a TCP connection and the HTTP/3 server has no corresponding QUIC stream deadline. An unauthenticated client can use a slow request body, trickling data indefinitely while holding a request and an upstream connection open and exhausting backends with bounded connection pools. This issue is fixed in 2.11.56 and 3.7.12.

Affected products

• Traefik: from 2.8.2 before 2.11.56; from 3.0.0 before 3.7.12 — fixed in 2.11.56, 3.7.12

How to fix

Upgrade to a fixed version: Traefik 2.11.56, 3.7.12. Check the vendor advisory for mitigations.

References

• https://github.com/traefik/traefik/commit/a8d0bc425859dde7481a6c9a324e610b81d754d0
• https://github.com/traefik/traefik/pull/13717
• https://github.com/traefik/traefik/releases/tag/v2.11.56
• https://github.com/traefik/traefik/releases/tag/v3.7.12
• https://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c

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