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CVE-2026-49375 JetBrains CVE debrief

A reflected cross-site scripting (XSS) vulnerability exists in JetBrains TeamCity versions prior to 2026.1 and 2025.11.5. The flaw affects the repository download page and could allow an attacker to execute malicious scripts in a victim's browser context. The CVSS 3.1 score of 6.1 (MEDIUM) reflects network attack vector, low attack complexity, no privileges required, but user interaction required, with scope change and low impacts to confidentiality and integrity. The vulnerability was published to the CVE database on May 29, 2026, and is currently undergoing analysis by NVD. JetBrains has addressed this issue in the specified fixed versions.

Vendor
JetBrains
Product
TeamCity
CVSS
MEDIUM 6.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-29
Original CVE updated
2026-07-22
Advisory published
2026-05-29
Advisory updated
2026-07-22

Who should care

Organizations running JetBrains TeamCity CI/CD servers, particularly those with externally accessible repository download pages. Security teams responsible for application security and developers using TeamCity for build automation.

Technical summary

Reflected XSS vulnerability in JetBrains TeamCity before 2026.1 and 2025.11.5 on the repository download page. CVSS 3.1 score 6.1 (MEDIUM). Fixed versions available.

Defensive priority

medium

Recommended defensive actions

  • Upgrade JetBrains TeamCity to version 2026.1 or 2025.11.5 or later
  • Review access logs for suspicious requests to the repository download page containing script tags or encoded JavaScript payloads
  • Implement Content Security Policy (CSP) headers as a defense-in-depth measure
  • Validate and sanitize all user-supplied input reflected in web page responses
  • Consider web application firewall (WAF) rules to detect and block XSS attempts

Evidence notes

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation). The affected product is confirmed as JetBrains TeamCity based on the CVE description and vendor reference. The fix versions are explicitly stated as 2026.1 and 2025.11.5.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-49375 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-49375

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-49375 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-49375

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.