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Fencer Vulns
high 7.5

CVE-2026-29054 json

Traefik: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)

published 2026-03-04 8 mo ago modified 2026-07-15 3 mo ago also EUVD-2026-9848 , GHSA-92mv-8f8w-wq52 , GO-2026-4597

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

Traefik is an HTTP reverse proxy and load balancer. From version 2.11.9 to 2.11.37 and from version 3.1.3 to 3.6.8, there is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a remote unauthenticated client can use lowercase Connection tokens (e.g. Connection: x-real-ip) to bypass the protection and trigger the removal of Traefik-managed forwarded identity headers. This issue has been patched in versions 2.11.38 and 3.6.9.

Patch / fix

  • go github.com/traefik/traefik/v2 2.11.38
  • go github.com/traefik/traefik/v3 3.6.9
  • Red Hat Red Hat OpenShift Dev Spaces 3.27 1776718585
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260317T205859-150000.1.152.1

suse advisories SUSE-SU-2026:1042-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • traefik openSUSE Tumbleweed 3.6.10-1.1
  • traefik2 openSUSE Tumbleweed 2.11.40-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10323-1openSUSE-SU-2026:10314-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-29054 updated cvss 7.5

github.com/traefik/traefik: Traefik: Information disclosure due to case-insensitive Connection header processing

  • Red Hat OpenShift Dev Spaces 3.27 devspaces 1776718585
    fixed: vendor fix RHSA-2026:10175
  • Red Hat OpenShift Dev Spaces 3.27 devspaces 1776716842, devspaces 1776717247, devspaces 1776718438, devspaces 1776718450, devspaces 1776718480, devspaces 1776743204, +9 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/traefik/traefik/v2
>=2.11.9, <2.11.38
2.11.38
go github.com/traefik/traefik/v3
>=3.1.3, <3.6.9
3.6.9
go github.com/traefik/traefik
all versions
 no fix listed

Affected products

  • traefik traefik
  • Red Hat Red Hat OpenShift Dev Spaces 3.27

Classification

Weakness
  • CWE-178 Improper Handling of Case Sensitivity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.