CVE-2025-52879VulnerabilityPublished 23 Jun 2025Updated 24 Jun 2025

CVE-2025-52879: JetBrains TeamCity · Cross-site Scripting

Affects JetBrains TeamCitySource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium : upgrade to 2025.03.3 when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

4.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.1% chance of exploitation in 30 days – higher than 67% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2025.03.3

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade org.jetbrains.teamcity/teamcity-server to 2025.03.3.

Affected software

Product	Affected	Fixed in
Mavenorg.jetbrains.teamcity/teamcity-server`pkg:maven/org.jetbrains.teamcity/teamcity-server`Other threats	Affected <2025.03.3	Fixed in 2025.03.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediate upgrade to JetBrains TeamCity version 2025.03.3 or later once available, as this version addresses the reflected XSS vulnerability in the NPM Registry integration. 2. Until patching is possible, restrict access to the TeamCity web interface to trusted networks and users, minimizing exposure to potential attackers. 3. Implement strict Content Security Policy (CSP) headers on the TeamCity server to limit the execution of unauthorized scripts and reduce the impact of XSS attacks. 4. Conduct user awareness training focused on phishing and social engineering risks, as user interaction is required for exploitation. 5. Review and harden user privileges within TeamCity, ensuring that only necessary users have high-level permissions to reduce the pool of potential attackers. 6. Monitor TeamCity logs and web traffic for unusual or suspicious requests that may indicate attempted exploitation of the reflected XSS vulnerability. 7. Employ web application firewalls (WAFs) with rules targeting reflected XSS patterns, specifically tuned for TeamCity’s NPM Registry integration endpoints. 8. Consider isolating CI/CD environments and enforcing network segmentation to limit lateral movement if an attacker exploits this vulnerability.

Description

In JetBrains TeamCity before 2025.03.3 reflected XSS in the NPM Registry integration was possible

Impact

For European organizations, the impact of this vulnerability can be significant, especially for those relying heavily on JetBrains TeamCity for their software development lifecycle automation. The reflected XSS could enable attackers to hijack authenticated sessions of privileged users, such as developers or DevOps engineers, leading to unauthorized access to build configurations, source code repositories, or deployment pipelines. This could result in the injection of malicious code into software builds, supply chain compromise, or leakage of sensitive intellectual property. Given the interconnected nature of CI/CD environments, even a medium-severity vulnerability can cascade into more severe consequences if leveraged as part of a multi-stage attack. The requirement for high privileges limits exploitation to insiders or attackers who have already gained some level of access, but the user interaction requirement means phishing or social engineering could be used to trigger the attack. European organizations in sectors with stringent compliance requirements (e.g., finance, healthcare, critical infrastructure) may face regulatory and reputational risks if such a vulnerability is exploited. Additionally, the scope change in the CVSS vector suggests that the vulnerability could affect multiple components or user roles, increasing the potential attack surface within affected environments.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

jetbrains.com/privacy-security/issues-fixed/ (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Jun 2025, 14:28 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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