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Vulnerabilities & CVEs BleepingComputer 3 weeks ago

CISA: Ransomware gangs now exploiting critical TeamCity flaw

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CyberNew Threat Research Desk
• Original Reporting: BleepingComputer
CyberNew Threat Intel Assessment
Assessed Severity: CRITICAL
Impacted Surface
Enterprise Perimeter & Network Defense
Intelligence Sector
Vulnerabilities & CVEs

Analyst Takeaway

"The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned federal agencies on Wednesday that ransomware gangs are now also exploiting a critical JetBrains TeamCity vulnerability patched in July. JetBrains patched the security flaw (tracked as CVE-2026-63077 ) on July 25 in TeamCity On-Premises versions 2025.11.7 and 2026.1.3, saying it is a critical authentication bypass..."

Recommended Defense & Mitigation

  • Emergency Patching: Prioritize vendor patches and CVE mitigation across internet-facing assets immediately.
  • Perimeter Audit: Inspect perimeter firewall logs and hunt for unauthorized RCE indicators.
Curated & Verified by CyberNew Threat Intelligence Desk Standard Defense Framework (NIST / MITRE ATT&CK)

TeamCity

​The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned federal agencies on Wednesday that ransomware gangs are now also exploiting a critical JetBrains TeamCity vulnerability patched in July.

JetBrains patched the security flaw (tracked as CVE-2026-63077) on July 25 in TeamCity On-Premises versions 2025.11.7 and 2026.1.3, saying it is a critical authentication bypass vulnerability that lets attackers with HTTP(S) access execute arbitrary operating system commands.

"An unauthenticated attacker could exploit the vulnerability via the TeamCity agent polling protocol to bypass authentication checks and execute arbitrary operating system commands with the privileges of the TeamCity server process," it said.

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Source Verification & Original Intelligence

This threat report was reviewed by CyberNew analysts and cross-referenced with primary security disclosures from BleepingComputer.

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