Exploited vulnerability · CISA KEV

Is CVE-2023-42793 exploited? Yes: in CISA KEV since 4 Oct 2023

Gociux · JetBrains TeamCity · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2023-42793, JetBrains TeamCity Authentication Bypass Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 4 Oct 2023, 15 days after it was published. It is known to be used in ransomware campaigns. It affects JetBrains TeamCity. If you run it, CISA's required action is: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What it is

JetBrains TeamCity contains an authentication bypass vulnerability that allows for remote code execution on TeamCity Server.

What to do

1. Check whether you run it. Look for TeamCity in your asset inventory, including appliances and cloud images. Stack check lists every exploited JetBrains CVE at once.
2. Apply the fix. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 19 Sep 2023.
4. Get told next time. Email alerts when CISA adds a CVE for JetBrains.

Other exploited CVEs in TeamCity

• CVE-2026-63077: JetBrains TeamCity Deserialization of Untrusted Data Vulnerability (5 Aug 2026)
• CVE-2024-27199: JetBrains TeamCity Relative Path Traversal Vulnerability (20 Apr 2026)
• CVE-2024-27198: JetBrains TeamCity Authentication Bypass Vulnerability (7 Mar 2024)

References

• blog.jetbrains.com/teamcity/2023/09/critical-security-issue-affecting-teamcity
• nvd.nist.gov/vuln/detail/CVE-2023-42793

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in October 2023 · JetBrains scorecard · act-now radar.