// CVE

CVE-2026-63077

Critical 9.8 Exploited (KEV)

JetBrains TeamCity

9.8CVSS
85%EPSS
YesCISA KEV

Summary

In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol

Published: 2026-07-27 · In KEV since: 2026-08-05

Analysis

🔴 Critical — actively exploited

Weakness: Insecure Deserialization (CWE-502). Untrusted serialized data leads to code execution.

How it's exploited: Exploitable over the network (internet-reachable), unauthenticated, no user interaction, and with low complexity.

⚠️ Critical combo: remote, unauthenticated and no interaction → trivial to automate.

Impact: Full compromise (confidentiality, integrity and availability).

Status: Active exploitation confirmed by CISA (KEV).

How to defend:
  • Patch now: it is in CISA's actively-exploited catalog (KEV), with a deadline.
  • Reduce exposure: keep it off the internet; firewall, VPN or network segmentation.
  • Detect: turn this CVE into detection rules.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The vector encodes how it's exploited (translated above, in the analysis). Break it down in the CVSS tool →

🔗 NVD record CISA KEV 🌉 CVE → detection 🎯 Am I exposed? ⚖️ Prioritize patch

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Sources: CISA KEV · EPSS · FIRST.org · NVD. Analysis derived from the CVSS vector and exploitation status (no AI). Informational; always verify against the vendor's official advisory.