JetBrains TeamCity Relative Path Traversal Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2026-04-20
• Known to be used in ransomware campaigns
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)

[ Description ]Official description

In JetBrains TeamCity before 2023.11.4 path traversal allowing to perform limited admin actions was possible

CISA: JetBrains TeamCity contains a relative path traversal vulnerability that could allow limited admin actions to be performed.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 4 May 2026): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• www.darkreading.com/cyberattacks-data-breaches/jetbrains-teamcity-mass-exploitation-und…Press/Media Coverage
• www.jetbrains.com/privacy-security/issues-fixedVendor Advisory
• github.com/Stuub/RCity-CVE-2024-27198/blob/main/RCity.pyExploit
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource