CVE-2026-63077
Critical 9.8 Exploited in the wild (KEV) Used in ransomware campaigns
Confirmed active exploitation — CISA KEV catalog
- Name
- JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Description
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
Metrics
- CVSS 3.1
-
9.8 (CRITICAL)
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 94% (percentile: 100) as of 1 November 2026
- CWE
- CWE-502
Affected products
jetbrains: teamcity
References
- https://www.jetbrains.com/privacy-security/issues-fixed/ Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026… US Government Resource