CVE-2025-26493

Medium

Published: 11 February 2025

Published

11 February 2025

Modified

16 May 2025

KEV Added

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Patch

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CVSS Score 4.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

EPSS Score 0.1567 94.8th percentile

Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-26493 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Jetbrains Teamcity. Its CVSS base score is 4.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 5.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-15 (Information Output Filtering) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly remediates the DOM-based XSS vulnerabilities by applying the JetBrains TeamCity 2024.12.2 patch as specified in the security bulletin.

SI-15 Information Output Filtering good match

prevent

Filters and encodes information output on the Code Inspection Report tab to prevent untrusted input from executing as script in the victim's browser.

SI-10 Information Input Validation partial match

prevent

Validates untrusted inputs to the Code Inspection Report tab against expected formats to block malicious XSS payloads before processing.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1059.007 JavaScript Execution

Adversaries may abuse various implementations of JavaScript for execution.

attack.mitre.org →

Why these techniques?

DOM-based XSS in network-accessible TeamCity web app enables exploitation of public-facing application (T1190) with arbitrary JavaScript execution in victim browser context (T1059.007) via crafted report payloads requiring user interaction.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

NVD Description

In JetBrains TeamCity before 2024.12.2 several DOM-based XSS were possible on the Code Inspection Report tab

Deeper analysisAI

CVE-2025-26493 is a set of DOM-based cross-site scripting (XSS) vulnerabilities, classified under CWE-79, affecting JetBrains TeamCity versions prior to 2024.12.2. These flaws exist specifically on the Code Inspection Report tab, where untrusted input could be executed in the victim's browser context. The vulnerability received a CVSS v3.1 base score of 4.6 (AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N), indicating medium severity with network accessibility, low attack complexity, and requirements for low privileges and user interaction.

An attacker with low-privileged access to a TeamCity instance could exploit these XSS issues by crafting malicious payloads targeted at the Code Inspection Report tab. Exploitation requires tricking an authenticated user—such as another team member or administrator—into interacting with the malicious content, for example by viewing a tampered report. Successful exploitation would enable limited impacts, including low-level disclosure of sensitive data in the browser (such as session tokens) or minor manipulation of page content, without affecting availability or escalating privileges.

JetBrains addressed these vulnerabilities in TeamCity 2024.12.2, as detailed in their security bulletin at https://www.jetbrains.com/privacy-security/issues-fixed/. Security practitioners should prioritize upgrading affected instances to the patched version and review access controls on the Code Inspection Report feature to minimize exposure.