Attackers Breached JetBrains Cadence via Unpatched TeamCity, Extracting AWS Credentials
Unknown attackers exploited critical TeamCity flaw CVE-2026-63077 to breach JetBrains Cadence, stealing a 2024 backup, user data, and AWS credentials; rotation urged.
JetBrains disclosed that threat actors exploited CVE-2026-63077 (CVSS 9.8), a TeamCity deserialization vulnerability added to CISA's KEV catalog on August 5, 2026, to breach its Cadence cloud computing service, with the intrusion running August 8-24, 2026. Confirmed access includes personal data (usernames, names, emails, login timestamps, IPs), a full 2024 Cadence server backup containing credentials and configuration, multiple AWS IAM users and secrets, files in JetBrains S3 buckets, and possibly PyCharm-synchronized source code. The compromised api.cadence.jetbrains.com server has been taken offline and all Cadence plugin access tokens invalidated. JetBrains urges users to immediately revoke or rotate all credentials used with Cadence and treat all executions, inputs, and outputs as potentially untrusted.