CVE-2026-25736

Name: CVE-2026-25736
Creator: NVD / NIST
Published: 2026-02-25T20:23:48.243+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.8/10EPSS 0.29%

Last modified Jun 17, 2026

CVE-2026-25736 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. Rucio is a software framework that provides functionality to organize, manage, and access large volumes of scientific data using customizable policies. Versions prior to 35.8.3, 38.5.4, and 39.3.1 have a stored Cross-Site Scripting (XSS) vulnerability in the Custom RSE Attribute of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. EPSS estimates a 0.29% chance of exploitation in the next 30 days.

Description

Rucio is a software framework that provides functionality to organize, manage, and access large volumes of scientific data using customizable policies. Versions prior to 35.8.3, 38.5.4, and 39.3.1 have a stored Cross-Site Scripting (XSS) vulnerability in the Custom RSE Attribute of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions. Versions 35.8.3, 38.5.4, and 39.3.1 fix the issue.

Metrics

CVSS 3.1

4.8/10

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

EPSS Probability

0.29%

20.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cern	Rucio	< 35.8.3
Cern	Rucio	>= 36.0.0, < 38.5.4
Cern	Rucio	>= 39.0.0, < 39.3.1

References

https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.htmlNot Applicable
https://github.com/rucio/rucio/releases/tag/35.8.3Product, Release Notes
https://github.com/rucio/rucio/releases/tag/38.5.4Product, Release Notes
https://github.com/rucio/rucio/releases/tag/39.3.1Product, Release Notes
https://github.com/rucio/rucio/security/advisories/GHSA-fq4f-4738-rqxmExploit, Vendor Advisory
https://github.com/rucio/rucio/security/advisories/GHSA-fq4f-4738-rqxmExploit, Vendor Advisory

Timeline

Published: Feb 25, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-25736?

How severe is CVE-2026-25736?

CVE-2026-25736 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2026-25736?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-25736?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST