Allows administrator takeover of a widely used CI server (TeamCity) via password-reset; can lead to pipeline/code/credential compromise across organizations.
CVE-2026-100255
Password-reset flaw in TeamCity allows administrator account takeover
Is CVE-2026-100255 being exploited?
Not confirmed. CVE-2026-100255 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.35% probability of exploitation in the next 30 days.
How severe is CVE-2026-100255?
CVE-2026-100255 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-100255?
Yes. A fix has been recorded for CVE-2026-100255. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100255 affect?
CVE-2026-100255 affects JetBrains TeamCity < 2026.2, TeamCity 2026.1.x < 2026.1.4, TeamCity 2025.11.x < 2025.11.8. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100255?
Upgrade TeamCity to 2026.2 or apply patches 2026.1.4 / 2025.11.8 immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Admin account takeover via password-reset; full CI control, modify pipelines, exfiltrate credentials, inject malicious builds.
Immediate action required
- affected< 2026.2, 2026.1.4, 2025.11.8
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.