CVEs / CVE-2026-63077
CVE-2026-63077: JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
- Known exploited in the CISA KEV catalog since 5 Aug 2026
- critical 9.8 CVSS 3.1 (from the CNA)
- EPSS 93.5% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
Are you affected? Check your servers with Stackurity: it lists the software on each server and the vulnerabilities to fix first.
Check your servers with Stackurity Already using Stackurity? Search for CVE-2026-63077
Summary
JetBrains TeamCity contains a deserialization of untrusted data vulnerability that could allow unauthenticated remote code execution via the agent polling protocol.
Description
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| JetBrains TeamCity | before 2026.1.3, 2025.11.7 | 2026.1.3, 2025.11.7 |
Exploitation
| In CISA KEV since | 5 Aug 2026 |
|---|---|
| Due date for US federal agencies | 8 Aug 2026 |
| Used in ransomware campaigns | Known |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-502 |
References
- CVE-2026-63077 on NVD
- CVE-2026-63077 in the CISA KEV catalog
- https://blog.jetbrains.com/teamcity/2026/07/cve-2026-63077/ (cited by CISA)
- https://www.jetbrains.com/privacy-security/issues-fixed/ (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.jetbrains.com/privacy-security/issues-fixed/ Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.