Upstream information
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: Resolved
This issue is currently rated as having important severity.
| CVSS detail | National Vulnerability Database | SUSE |
|---|---|---|
| Base Score | 8.8 | 7.7 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N |
| Attack Vector | Network | Network |
| Attack Complexity | Low | High |
| Privileges Required | Low | High |
| User Interaction | None | None |
| Scope | Unchanged | Changed |
| Confidentiality Impact | High | High |
| Integrity Impact | High | High |
| Availability Impact | High | None |
| CVSSv3 Version | 3.1 | 3.1 |
| 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 Security Advisories:
- SUSE-SU-2026:1205-1, published 2026-04-07T14:18:21Z
List of released packages
| Product(s) | Fixed package version(s) | References |
|---|
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| openSUSE Leap 15.6 | govulncheck-vulndb | Released |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | govulncheck-vulndb | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | govulncheck-vulndb | Affected |
| openSUSE Leap 15.5 | govulncheck-vulndb | Affected |
SUSE Timeline for this CVE
CVE page created: Fri Mar 27 18:29:44 2026CVE page last modified: Thu Apr 16 14:57:46 2026