---
id: "CVE-2026-63077"
kind: "vulnerability"
aliases: ["CVE-2026-63077"]
title: "In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "jetbrains teamcity", "fixed": ["2025.11.7"], "affected": "< 2025.11.7", "ecosystem": "vendor"}, {"name": "jetbrains teamcity", "fixed": ["2026.1.3"], "affected": ">= 2026.1, < 2026.1.3", "ecosystem": "vendor"}, {"name": "JetBrains TeamCity", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ci-cd", "exploited", "jetbrains", "ransomware", "self-hosted", "teamcity", "vendor"]
not_affected_if: ["managed-hosting", "no-teamcity-deployment"]
published_at: "2026-07-27T17:16:38+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:50+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-63077", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63077", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

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

JetBrains TeamCity has a deserialization of untrusted data flaw that lets an unauthenticated remote attacker run code on the server through the agent polling protocol. CISA lists it as actively exploited in the wild, with ransomware use noted in the source tags.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:jetbrains teamcity affected < 2025.11.7 fixed 2025.11.7
- vendor:jetbrains teamcity affected >= 2026.1, < 2026.1.3 fixed 2026.1.3
- vendor:JetBrains TeamCity affected ? fixed ?

## How to check

Identify every TeamCity server version in use and check whether its agent polling port is reachable from the internet or untrusted networks; the sources do not give an affected version range or a specific command.

## Fix

Apply the JetBrains vendor patch or mitigation for CVE-2026-63077 as CISA directs; the fixed version is not stated in the sources. If no mitigation exists, discontinue exposing or using the affected TeamCity instance.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-63077
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-63077

## From the sources

JetBrains TeamCity contains a deserialization of untrusted data vulnerability that could allow unauthenticated remote code execution via the agent polling protocol.

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_