Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass
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..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.
CVE-2026-88878
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-88878
traefik
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
traefik
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "traefik",
"product": "traefik",
"versions": [
{
"status": "affected",
"version": "2.8.2",
"versionType": "semver",
"lessThanOrEqual": "3.7.13"
}
],
"packageURL": "pkg:golang/github.com/traefik/traefik/v2",
"defaultStatus": "unaffected"
},
{
"vendor": "traefik",
"product": "traefik",
"versions": [
{
"status": "affected",
"version": "3.0.0",
"versionType": "semver",
"lessThanOrEqual": "3.7.13"
}
],
"packageURL": "pkg:golang/github.com/traefik/traefik/v3",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-88878
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #12955 · Revision 1
- Added to Heist Feed
- Publisher date