Act
archived
TeamCity On-Premises Critical RCE CVE-2026-63077 (CVSS 9.8)
- Engineer — Act: A public PoC on GitHub combined with a CVSS 9.8 unauthenticated RCE makes exploitation imminent — patch all on-premises TeamCity instances to 2025.11.7 or 2026.1.3 immediately; Cloud instances are already remediated.
- SOC/IR — Act: With a public PoC now available, begin hunting for unauthenticated requests to TeamCity build/run endpoints and review build agent logs for unexpected OS command execution patterns since the PoC publication date.
- Leader — Plan: Confirm whether your organization runs TeamCity On-Premises and verify the engineering team has prioritized emergency patching this week — a compromise of CI/CD pipelines carries supply-chain risk that could generate customer or board questions if exploitation is later confirmed.
- Signals: CVE-2026-63077 — CISA KEV: not listed, EPSS n/a, public PoC on GitHub
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