Unauthenticated RCE in a widely used CI product (TeamCity) can compromise build infrastructure and artifacts, causing organization-wide disruption.
CVE-2026-63077
Unauthenticated RCE in JetBrains TeamCity agent polling protocol.
Is CVE-2026-63077 being exploited?
Yes. CVE-2026-63077 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2026-63077?
CVE-2026-63077 is rated Critical. 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-2026-63077?
Yes. A fix has been recorded for CVE-2026-63077. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63077 affect?
CVE-2026-63077 affects JetBrains TeamCity Server (<2026.1.3, <2025.11.7), TeamCity Build Agents. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63077?
Upgrade TeamCity to 2026.1.3 or 2025.11.7+, restrict agent access, and review builds.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote code execution on TeamCity server via agent polling, enabling arbitrary code execution, build/artifact compromise, and lateral movement.
Immediate action required
- affected< 2026.1.3, 2025.11.7
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.