Authenticated remote command execution in widely used CI server (JetBrains TeamCity) can lead to code execution and lateral movement across organizations.
CVE-2026-100254
Authenticated RCE via CRLF injection in TeamCity Git pipeline settings
Is CVE-2026-100254 being exploited?
Not confirmed. CVE-2026-100254 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 0.46% probability of exploitation in the next 30 days.
How severe is CVE-2026-100254?
CVE-2026-100254 is rated High with a CVSS score of 8.8. 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-2026-100254?
Yes. A fix has been recorded for CVE-2026-100254. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100254 affect?
CVE-2026-100254 affects JetBrains TeamCity (versions prior to 2026.2; fixed in 2026.2, 2026.1.4, 2025.11.8). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100254?
Upgrade to fixed TeamCity versions; restrict access and rotate credentials.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attackers can execute arbitrary commands on Windows servers hosting TeamCity via CRLF injection, enabling remote code execution and lateral movement.
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.