CVE-2026-88012
published 2026-09-10CVE-2026-88012: 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…
PriorityP432medium5.3CVSS 3.1
AVNACLPRNUINSUCNINAL
EPSS
0.52%
43.0th percentile
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
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| devspaces | traefik-rhel9 | — | — |
| github.com | traefik_traefik_v2 | >= 2.8.2 < 2.11.56 | 2.11.56 |
| github.com | traefik_traefik_v3 | >= 3.0.0 < 3.7.12 | 3.7.12 |
| traefik | traefik | — | — |
| traefik | traefik | — | — |
| traefik | traefik | >= 2.8.2 < 2.11.56 | 2.11.56 |
| traefik | traefik | >= 3.0.0 < 3.7.12 | 3.7.12 |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
vendor_redhat5.3MEDIUM
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GHSA
Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded
ghsa·2026-09-10
CVE-2026-88012 [MEDIUM] CWE-770 Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded
Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded
## Summary
There is a medium severity vulnerability in Traefik's HTTP/3 entry points: the `respondingTimeouts` settings were not applied to the HTTP/3 request path. `readTimeout` in particular is on by default at 60s and is documented as bounding the time to read the entire request including its body, but it is enforced as a deadline on the TCP connection, which cannot reach a QUIC stream, and Traefik's HTTP/3 server was constructed with no timeout of any kind. An unauthenticated client that trickles a request body therefore holds a request open for as long as it chooses, and with it one upstream connection per request, at negligible cost to itself. Backends with bounded connection pools
Red Hat
traefik: Traefik: Denial of Service via slow HTTP/3 request bodies
vendor_redhat·2026-09-10·CVSS 5.3
CVE-2026-88012 [MEDIUM] CWE-770 traefik: Traefik: Denial of Service via slow HTTP/3 request bodies
traefik: Traefik: Denial of Service via slow HTTP/3 request bodies
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.
A flaw was found in Traefik, an open-source HTTP reverse proxy and load balancer. Its HTTP/3 entrypoints do not correctly apply read timeouts, which are intended to prevent prolonged connect
No detection rules found.
No public exploits indexed.
https://github.com/traefik/traefik/commit/a8d0bc425859dde7481a6c9a324e610b81d754d0https://github.com/traefik/traefik/pull/13717https://github.com/traefik/traefik/releases/tag/v2.11.56https://github.com/traefik/traefik/releases/tag/v3.7.12https://github.com/traefik/traefik/security/advisories/GHSA-7ghq-v6jf-g56c
2026-09-10
Published