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Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

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
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