6.9

CVE-2026-88878: Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass

Published
AliasesCGA-7f6m-jv4c-g2j2CGA-7m4j-389v-9r9c
Published 10-09-2026Last modified 08-10-2026

Vulnerability summary

CVE-2026-88878 is a medium (CVSS 6.9) vulnerability in traefik. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 36.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.42%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 10-09-2026
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

Description

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.<name>.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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.42% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard1 product
  • traefik-3.6All versions (No fix recorded)
Traefik1 product
  • traefik≥ 2.8.2, ≤ 3.7.13 | ≥ 3.0.0, ≤ 3.7.13
Wolfi1 product
  • traefik-3.6All versions (No fix recorded)

3 vendors · 3 products

References

4 links