CVE-2026-25138

Rucio WebUI has Username Enumeration via Login Error Message

MEDIUM
5.3
CVSS Score
Published: February 25, 2026 at 07:28 PM UTC
Updated: June 17, 2026 at 10:24 AM UTC
2 products affected across 2 vendorsRucioRucio

Using rucio by rucio?

Get instant alerts when new vulnerabilities affect rucio - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 35.8.336.0.0 ≤ v < 38.5.439.0.0 ≤ v < 39.3.1
v < 35.8.3v < 38.5.4v < 39.3.1
Affected range stops below 35.8.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 38.5.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 39.3.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (5)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/rucio/rucio/security/advisories/GHSA-38wq-6q2w-hcf9
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/rucio/rucio/releases/tag/35.8.3
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/rucio/rucio/releases/tag/38.5.4
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/rucio/rucio/releases/tag/39.3.1

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-204

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card