Vulnerability in Cern Rucio
CVE-2026-25138
Rucio is a software framework that provides functionality to organize, manage, and access large volumes of scientific data using customizable policies. Prior to versions 35.8.3, 38.5.4, and 39.3.1, the WebUI login endpoint returns distinct error messages depending on whether a supplied username exists, allowing unauthenticated attackers to enumerate valid usernames. Versions 35.8.3, 38.5.4, and 39.3.1 fix the issue.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (26.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Cern Rucio
- Rucio — versions < 35.8.3, >= 36.0.0rc1, < 38.5.4, >= 39.0.0rc1, < 39.3.1
Weakness classification (CWE)
References
- github.com/rucio/rucio/security/advisories/GHSA-38wq-6q2w-hcf9 (Exploit, Vendor Advisory)
- cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html (Not Applicable)
- github.com/rucio/rucio/releases/tag/35.8.3 (Product, Release Notes)
- github.com/rucio/rucio/releases/tag/38.5.4 (Product, Release Notes)
- github.com/rucio/rucio/releases/tag/39.3.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-25138?
- CVE-2026-25138 is a medium-severity vulnerability in Cern Rucio, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-02-25.
- How severe is CVE-2026-25138?
- Medium severity. CVSS v3 base score is 5.3 out of 10.