CVE-2026-63077
JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 8 August 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 86.52% probability · 100th percentile
- CISA KEV
- Listed 5 August 2026 · due 8 August 2026
- Weakness
- CWE-502
- Affected
- jetbrains/teamcity
- Source
- cve@jetbrains.com
CISA notes
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. https://blog.jetbrains.com/teamcity/2026/07/cve-2026-63077/; https://www.jetbrains.com/privacy-security/issues-fixed/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-63077
References
- https://www.jetbrains.com/privacy-security/issues-fixed/Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.