CVE-2026-88007 Traefik - Authentication Bypass

Traefik 2.11.0 to 2.11.57 and 3.7.13 contain an authentication bypass caused by shared backend transport usage in HTTP/3 ConnContext, letting attackers reuse authenticated backend connections to impersonate victims, exploit requires HTTP/3 and connection-bound NTLM or Negotiate authentication enabled.

CVSS base score 9.1 /10
Critical
CISA KEV
Not listed
Public exploit
None known
EPSS
0.60% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Authentication Bypass
Impact
Broken Authentication, Information Disclosure
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
10 September 2026
Updated
15 October 2026
Weakness
CWE-287

Vendor fix

Update to versions 2.11.57 or 3.7.13 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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