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Fencer Vulns
medium 6.1

CVE-2026-25736 json

Rucio WebUI has a Stored Cross-site Scripting (XSS) Vulnerability in its Custom RSE Attribute

published 2026-02-25 8 mo ago modified 2026-07-13 3 mo ago also GHSA-fq4f-4738-rqxm , PYSEC-2026-3055 , EUVD-2026-8729

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi rucio-webui 35.8.3, 38.5.4, 39.3.1
  • cern rucio 35.8.3, 38.5.4, 39.3.1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
8 mo ago

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/rucio/rucio/security/advisories/GHSA-fq4f-4738-rqxm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
GitHub 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
OSV 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi rucio-webui
<35.8.3
>=36.0.0rc1, <38.5.4
>=39.0.0rc1, <39.3.1
35.8.3
38.5.4
39.3.1

Affected products

  • rucio rucio

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-1004 Sensitive Cookie Without 'HttpOnly' Flag

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.