Critical severity · published Apr 30, 2026
CVE-2026-35051
Traefik: ForwardAuth trustForwardHeader=false allows spoofed X-Forwarded-Prefix to bypass auth
10.0
CVSS
0.3%
EPSS
No
On KEV
Description
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is an authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TR
traefik · traefik
< 2.11.43; >= 3.0.0-beta1, < 3.6.14; >= 3.7.0-ea.1, < 3.7.0-rc.2 · source: vendor, NVD
RH
Red Hat OpenShift Dev Spaces 3.28 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35051
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-35051
Product
https://github.com/traefik/traefik/releases/tag/v2.11.43
Product
https://github.com/traefik/traefik/releases/tag/v3.6.14
Product
https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2
Exploit
https://github.com/traefik/traefik/security/advisories/GHSA-6384-m2mw-rf54
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:21772
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-35051
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