JetBrains flaws being used in attacks

CISA lists 4 flaws in JetBrains products as being used in attacks, most recently on 5 Aug 2026. All have been used in ransomware.

What to do

1. Update every JetBrains product you use.Install the updates JetBrains offers, on every device, and restart when asked. Each flaw below has a fix or clear advice; that’s one of CISA’s conditions for listing it.
2. If someone looks after IT for you, send them this page.Many of these are in equipment you don’t see: routers, firewalls, servers, the office network. Ask them to confirm each one is fixed, or that you don’t use the product.
3. Check anything else in the lookup.Search any app, company or CVE. Not being on CISA’s list doesn’t mean safe: keep updating either way.

Every flaw, newest first

1. Being used in attacksUsed in ransomwareAdded by CISA on 5 Aug 2026
   JetBrains TeamCity
   CVE-2026-63077JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
   JetBrains TeamCity contains a deserialization of untrusted data vulnerability that could allow unauthenticated remote code execution via the agent polling protocol.
   CISA’s required actionApply 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). Read all

   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.
   CVE recordNVD
2. Being used in attacksUsed in ransomwareAdded by CISA on 20 Apr 2026
   JetBrains TeamCity
   CVE-2024-27199JetBrains TeamCity Relative Path Traversal Vulnerability
   JetBrains TeamCity contains a relative path traversal vulnerability that could allow limited admin actions to be performed.
   CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD
3. Being used in attacksUsed in ransomwareAdded by CISA on 7 Mar 2024
   JetBrains TeamCity
   CVE-2024-27198JetBrains TeamCity Authentication Bypass Vulnerability
   JetBrains TeamCity contains an authentication bypass vulnerability that allows an attacker to perform admin actions.
   CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD
4. Being used in attacksUsed in ransomwareAdded by CISA on 4 Oct 2023
   JetBrains TeamCity
   CVE-2023-42793JetBrains TeamCity Authentication Bypass Vulnerability
   JetBrains TeamCity contains an authentication bypass vulnerability that allows for remote code execution on TeamCity Server.
   CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD

From CISA’s Known Exploited Vulnerabilities catalog, updated 21 Oct 2026 (version 2026.10.21). CISA’s required actions are written for US government agencies. JetBrains on CISA’s site.