Improper Validation of Unsafe Equivalence in Input in TeamCity - CVE-2026-100255
Published: October 2, 2026
Vulnerability identifier: #VU153133
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-100255
CWE-ID: CWE-1289
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to take over an administrator account.
The vulnerability exists due to improper validation of unsafe equivalence in input in the password reset process when processing password reset requests. A remote attacker can reset an administrator account password to take over an administrator account.
Affected software
TeamCity
How to mitigate CVE-2026-100255
Install security update from vendor's website.
TeamCity - addressed in versions 2025.11.8, 2026.1.4, 2026.2