Upstream information

CVE-2026-121966 at MITRE

Description

Traefik 2.x before 2.11.60 and 3.x before 3.7.16 sends ForwardAuth subrequests (and, in 3.7, Ingress NGINX auth-url requests) through an auth-server connection pool shared by all clients, exposing connection-bound NTLM or Negotiate authentication. An unauthenticated attacker can reuse another user's authenticated connection, receiving the victim's identity via authResponseHeaders to access backends as that user.

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 CNA (VulnCheck) SUSE
Base Score 8.7 8.7
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Attack Vector Network Network
Attack Complexity High High
Privileges Required None None
User Interaction None None
Scope Changed Changed
Confidentiality Impact High High
Integrity Impact High High
Availability Impact None None
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail CNA (VulnCheck) SUSE
Base Score 7 7
Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/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:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Attack Vector Network Network
Attack Complexity Low High
Attack Requirements Present Present
Privileges Required None None
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: 1289554 [NEW]

No SUSE Security Announcements cross referenced.

SUSE Timeline for this CVE

CVE page created: Thu Nov 5 20:00:58 2026
CVE page last modified: Fri Nov 6 17:00:21 2026