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.
CVE-2026-25138
This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 75% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(medium)
- EG Risk
- 28(Track)EG Risk 28/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity53% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 26%
- KEV
- Not listed
Published
February 25, 2026
Last Modified
June 17, 2026
Advisory Details (5)
Auto-updated Aug 6, 2026Username Enumeration via Login Error Message in Rucio WebUI · Advisory · rucio/rucio · GitHub
https://github.com/rucio/rucio/security/advisories/GHSA-38wq-6q2w-hcf9Rucio 39.3.1 patch release
Patch available: rucio/rucio 39.3.1
https://github.com/rucio/rucio/releases/tag/39.3.1Rucio 38.5.4 LTS patch release
Patch available: rucio/rucio 38.5.4
https://github.com/rucio/rucio/releases/tag/38.5.4Rucio 35.8.3 LTS patch release
Patch available: rucio/rucio 35.8.3
https://github.com/rucio/rucio/releases/tag/35.8.3Authentication - OWASP Cheat Sheet Series
https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html#authentication-and-error-messagesAffected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rucio-webui | 1.10.0 ... 39.3.0 (452 versions) | 39.3.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 26× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 19:36 UTCOSV refresh
- 2026-09-18 19:27 UTCEPSS rescore
- 2026-09-16 14:07 UTCEPSS rescore
- 2026-09-16 05:15 UTCEPSS rescore
- 2026-09-13 16:47 UTCEPSS rescore
- 2026-09-12 15:01 UTCEPSS rescore
- 2026-09-11 14:52 UTCEPSS rescore
- 2026-09-10 09:34 UTCEPSS rescore
- 2026-09-08 22:00 UTCEPSS rescore
- 2026-09-07 16:01 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
- 2026-09-04 05:06 UTCEPSS rescore
- 2026-09-02 14:11 UTCEPSS rescore
- 2026-09-01 13:53 UTCEPSS rescore
- 2026-09-01 04:39 UTCEPSS rescore
- 2026-08-30 22:47 UTCOSV refresh
- 2026-08-30 19:17 UTCEPSS rescore
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-28 21:41 UTCEPSS rescore
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-26 14:46 UTCEPSS rescore
- 2026-08-25 13:48 UTCEPSS rescore
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
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- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 08:59 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 01:00 UTCEG score recompute
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-11 13:42 UTCEPSS rescore
- 2026-08-11 08:56 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 08:46 UTCEG score recompute
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 08:37 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-07 20:41 UTCEG score recompute
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 02:59 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-02 19:32 UTCEG score recompute
- 2026-08-02 02:26 UTCEPSS rescore
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-27 14:04 UTCEG score recompute
- 2026-07-27 13:57 UTCOSV refresh
Frequently asked(5)
What is CVE-2026-25138?
When was CVE-2026-25138 disclosed?
Is CVE-2026-25138 actively exploited?
What is the CVSS score of CVE-2026-25138?
How do I remediate CVE-2026-25138?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-25138
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