---
id: 6132
title: "CVE-2026-63077: JetBrains TeamCity unauthenticated RCE with public PoC and active exploitation"
cve: CVE-2026-63077
cvss: 9.8
severity: critical
vendor: "JetBrains"
product: "TeamCity On-Premises"
affected_versions: "All TeamCity On-Premises versions; fixed in 2025.11.7 and 2026.1.3"
source_domain: github.com
source_url: "https://github.com/sfewer-r7/CVE-2026-63077"
published_at: "2026-08-07T08:38:01Z"
tags: ["active-exploitation", "rce", "public-poc", "featured", "jetbrains", "teamcity", "deserialization", "ci-cd", "poc", "cve-2026-63077"]
phying_url: "https://phying.com/item/6132"
lang: en
---

# CVE-2026-63077: JetBrains TeamCity unauthenticated RCE with public PoC and active exploitation

## Summary

This public PoC demonstrates unauthenticated remote code execution in JetBrains TeamCity On-Premises through the agent polling protocol and unsafe deserialization. The issue affects TeamCity On-Premises; fixes are available in 2025.11.7 and 2026.1.3. CISA added the vulnerability to KEV on August 5, 2026, confirming active exploitation. The JetBrains-hosted TeamCity service is not affected.

## Why it matters

An unauthenticated attacker who can reach a TeamCity HTTP(S) service may execute arbitrary operating-system commands with the TeamCity server process privileges, exposing configuration and credentials, changing server state, and compromising build artifacts or downstream CI/CD pipelines. CISA KEV now confirms active exploitation. Upgrade to 2025.11.7, 2026.1.3, or later immediately; if upgrading is not possible, apply JetBrains' security patch plugin, restrict internet access, rotate exposed credentials, and investigate potentially exposed instances.

## Intelligence Metadata

- **Sources:** github.com
- **CVE:** CVE-2026-63077
- **CVSS:** 9.8
- **Vendor:** JetBrains
- **Product:** TeamCity On-Premises
- **Affected versions:** All TeamCity On-Premises versions; fixed in 2025.11.7 and 2026.1.3
- **Published:** 2026-08-07T08:38:01Z
- **Original:** https://github.com/sfewer-r7/CVE-2026-63077
- **Phying News:** https://phying.com/item/6132