Upstream information

CVE-2026-33433 at MITRE

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.42, 3.6.11, and 3.7.0-ea.3, when `headerField` is configured with a non-canonical HTTP header name (e.g., `x-auth-user` instead of `X-Auth-User`), an authenticated attacker can inject their own canonical version of that header to impersonate any identity to the backend. The backend receives two header entries - the attacker-injected canonical one is read first, overriding Traefik's non-canonical write. Versions 2.11.42, 3.6.11, and 3.7.0-ea.3 patch the issue.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail SUSE
Base Score 7.7
Vector CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N
Attack Vector Network
Attack Complexity High
Privileges Required High
User Interaction None
Scope Changed
Confidentiality Impact High
Integrity Impact High
Availability Impact None
CVSSv3 Version 3.1
CVSS v4 Scores
CVSS detail CNA (GitHub) SUSE
Base Score 5.1 5.1
Vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Attack Vector Network Network
Attack Complexity High High
Attack Requirements Present Present
Privileges Required High High
User Interaction None None
Vulnerable System Confidentiality Impact None None
Vulnerable System Integrity Impact None None
Vulnerable System Availability Impact None None
Subsequent System Confidentiality Impact High High
Subsequent System Integrity Impact High High
Subsequent System Availability Impact None None
CVSSv4 Version 4.0 4.0
SUSE Bugzilla entry: 1261016 [NEW]

No SUSE Security Announcements cross referenced.

SUSE Timeline for this CVE

CVE page created: Fri Mar 27 18:29:44 2026
CVE page last modified: Tue Mar 31 02:02:42 2026