JetBrains

JetBrains TeamCity CVE-2026-63077 Actively Exploited in the Wild, JPCERT Urges Immediate Patching and Breach Investigation

A critical deserialization vulnerability tracked as CVE-2026-63077 has been discovered in JetBrains TeamCity, allowing unauthenticated remote code execution through the agent polling protocol. The flaw was privately reported to JetBrains on July 10, 2026, and publicly disclosed on July 27 with patches released in TeamCity 2026.1.3 and 2025.11.7. Following disclosure, active exploitation was confirmed, prompting CISA to add the vulnerability to its Known Exploited Vulnerabilities Catalog on August 5 and mandate federal agencies to remediate by August 8. JetBrains issued its own exploitation warning on August 7. JPCERT/CC has verified that affected versions remain in use within Japan and notes that public exploit code is now available, recommending organizations verify their deployments, apply updates promptly, and conduct compromise assessments.

CISA Adds JetBrains TeamCity CVE-2026-63077 to Known Exploited Vulnerabilities Catalog After Active Attacks

The US Cybersecurity and Infrastructure Security Agency has added a critical vulnerability in JetBrains TeamCity to its Known Exploited Vulnerabilities catalog due to confirmed exploitation in the wild. The flaw, tracked as CVE-2026-63077, stems from unsafe deserialization of untrusted data over the agent polling protocol and permits unauthenticated remote code execution. TeamCity is widely used for automating software build, test, and deployment pipelines in development environments. CISA directed all US federal agencies to apply vendor mitigations within three days, by August 8, 2026. Organizations running the continuous integration server are urged to review exposure and implement the recommended fixes immediately to prevent further compromise.

Critical Vulnerability in JetBrains TeamCity Allows Unauthenticated Remote Code Execution

JetBrains has disclosed a critical vulnerability in its on-premises TeamCity CI/CD server that permits remote attackers to execute arbitrary operating system commands without authentication. The flaw, tracked as CVE-2026-63077, affects the agent polling protocol and can be exploited simply by accessing the TeamCity Server over HTTP or HTTPS. With a CVSSv3.1 base score of 9.8, the issue is rated Critical and could lead to data theft, configuration changes, or compromise of build artifacts and downstream pipelines. No in-the-wild exploitation had been observed at the time of disclosure. JetBrains has released fixed versions TeamCity 2026.1.3 and 2025.11.7, along with a patch plugin for all releases since 2017.1, and recommends restricting external access until updates can be applied.

Critical Vulnerabilities in JetBrains IntelliJ IDEA and TeamCity Enable Remote Code Execution

JetBrains has addressed multiple critical vulnerabilities in its IntelliJ IDEA and TeamCity products that could allow remote code execution, unauthorized file access, and sandbox escapes. The flaws affect remote development environments and require immediate patching, especially in shared setups. In IntelliJ IDEA, CVE-2026-59792 involves directory traversal during workspace identifier processing and carries a CVSS score of up to 9.8. TeamCity received fixes for several issues, including malicious Git repository configurations that enable code execution and a Kotlin DSL sandbox escape. Additional patches cover arbitrary file access through Perforce integration and a persistent cross-site scripting flaw on cloud profile pages. Administrators are urged to update IntelliJ IDEA to versions 2026.1.4 or 2026.2 and TeamCity to 2026.1.2 or 2025.11.6 depending on the release line in use.