Deserialization in Jetbrains Teamcity
CVE-2026-63077
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.896 (99.8th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.098 · newest: 0.896 · change: +0.798
Affected products
- Jetbrains Teamcity — versions 0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- www.jetbrains.com/privacy-security/issues-fixed/ (Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2026-63077?
- CVE-2026-63077 is a critical-severity vulnerability in Jetbrains Teamcity, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-07-27.
- How severe is CVE-2026-63077?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-63077 known to be exploited?
- Yes. CVE-2026-63077 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-08-05), indicating it is being actively exploited. 8 public proof-of-concept repositories are indexed.