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CVE-2026-63077 JetBrains CVE debrief

CVE-2026-63077 is a critical vulnerability in JetBrains TeamCity, allowing unauthenticated remote code execution via the agent polling protocol. The issue exists in versions before 2026.1.3 and 2025.11.7. This vulnerability has a CVSS score of 9.8 and is classified as CRITICAL, indicating a high impact on confidentiality, integrity, and availability. Users of JetBrains TeamCity should prioritize patching this vulnerability to prevent potential remote code execution attacks. The vulnerability affects the agent polling protocol, which could be exploited by attackers to execute arbitrary code on affected systems.

Vendor
JetBrains
Product
TeamCity
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-27
Original CVE updated
2026-07-27
Advisory published
2026-07-27
Advisory updated
2026-07-27

Who should care

Users of JetBrains TeamCity, particularly those responsible for patching and vulnerability management, should prioritize patching this vulnerability to prevent potential remote code execution attacks. Additionally, security teams and operators managing TeamCity instances should be aware of the vulnerability and take steps to mitigate its impact. This includes reviewing the official advisory, verifying affected scope, and applying patches or mitigations as recommended by the vendor.

Technical summary

The vulnerability, CVE-2026-63077, has a CVSS score of 9.8 and is classified as CRITICAL. It allows unauthenticated remote code execution via the agent polling protocol in JetBrains TeamCity before versions 2026.1.3 and 2025.11.7. The CVSS vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating a high impact on confidentiality, integrity, and availability. The vulnerability affects the agent polling protocol, which could be exploited by attackers to execute arbitrary code on affected systems.

Defensive priority

High priority should be given to patching CVE-2026-63077 due to its critical severity and potential for remote code execution.

Recommended defensive actions

  • Apply patches for JetBrains TeamCity versions 2026.1.3 or 2025.11.7 and later.
  • Restrict access to the agent polling protocol.
  • Monitor TeamCity instances for suspicious activity.
  • Inventory and update affected systems.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.

Evidence notes

The CVE record for CVE-2026-63077 was published on 2026-07-27T17:16:38.830Z and last modified on 2026-07-27T18:16:57.483Z. The NVD entry is currently marked as Received. Evidence is limited to the information provided in the CVE and NVD entries. Defenders should verify the affected scope and severity with JetBrains and review the official advisory for guidance on patching and mitigation. The agent polling protocol vulnerability allows unauthenticated remote code execution, which could lead to high impact on confidentiality, integrity, and availability.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-27T17:16:38.830Z and has not been modified since then. The NVD entry is currently Received.