JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
JetBrains — TeamCity
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
9.8
10.7%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- Jul 27, 2026
- Modified
- Aug 6, 2026
- Added to KEV
- Aug 5, 2026
- Federal patch due
- Aug 8, 2026
CISA 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.
Weakness classification
Affected packages
Proof-of-concept & exploitation references
4 foundWeaponization
Public repositories whose name or description references CVE-2026-63077, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
- sfewer-r7/CVE-2026-63077★ 19
Unauthenticated Remote Code Execution in JetBrains TeamCity (CVE-2026-63077)
updated Aug 18, 2026
- unveiledhistory49/teamcity-cve-2026-63077-remediation★ 1
JetBrains TeamCity On-Premises CVE-2026-63077 Emergency Hardening & Patch Runbook Package
updated Aug 19, 2026
- AnggaTechI/CVE-2026-63077★ 0
CVE-2026-63077 — Unauthenticated Remote Code Execution in JetBrains TeamCity via agent polling protocol deserialization. CVSS 9.8 CRITICAL. Mass exploitation tool with interactive shell, multi-threading, and real-time result logging.
updated Aug 11, 2026
- BoredHackerBlog/teamcity-CVE-2026-63077-pcap★ 0
teamcity teamcity-CVE-2026-63077 exploitation pcap
updated Aug 10, 2026
References
Frequently asked questions
What is CVE-2026-63077?
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
How severe is CVE-2026-63077?
CVE-2026-63077 has a CVSS base score of 9.8 out of 10 (CVSS 3.1).
Is CVE-2026-63077 actively exploited in the wild?
Yes. CVE-2026-63077 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Aug 5, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-63077?
10.7% - meaning FIRST.org's EPSS model estimates a 10.7% probability this vulnerability will be exploited in the wild within 30 days (95% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-63077?
Yes - a public Nuclei template referencing CVE-2026-63077 exist in public repositories we checked. We also found 4 public GitHub repositories referencing this CVE.
What type of vulnerability is CVE-2026-63077?
CVE-2026-63077 is classified under CWE-502.
Cross-checked against
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