Security readout for executives and security teams
Plain-English summary
Rucio WebUI versions before the fixed releases can reflect attacker-controlled content in a 500 error message. If a logged-in user opens a crafted URL, an attacker could run script in that user’s browser and potentially steal login session tokens. This is most urgent for organizations exposing Rucio WebUI to users or the internet.
Executive priority
Prioritize remediation for any exposed or business-critical Rucio WebUI. The issue can compromise user sessions but requires a user to open a crafted link. Patch during the next urgent maintenance window, faster for internet-facing deployments.
Technical view
CVE-2026-25136 is a reflected XSS in Rucio WebUI ExceptionMessage rendering for 500 errors. Affected ranges are <35.8.3, 36.0.0rc1 to <38.5.4, and 39.0.0rc1 to <39.3.1. CVSS 3.1 is 8.1, with network access, low complexity, no privileges, and required user interaction. Related CWEs are CWE-79 and CWE-1004.
Likely exposure
Exposure is likely where affected Rucio WebUI versions are reachable by authenticated users. Risk increases if the WebUI is internet-accessible, used by many researchers/operators, or session cookies are not strongly protected.
Exploitation context
The advisory describes token theft via a specially crafted URL, requiring user interaction. The source bundle does not indicate known active exploitation, and KEV status is false.
Researcher notes
The key condition is unsafe rendering of ExceptionMessage in WebUI 500 error handling. Avoid assuming exploit availability beyond the advisory. Validate by version and configuration review rather than offensive testing unless explicitly authorized.
Mitigation direction
- Upgrade Rucio to 35.8.3, 38.5.4, or 39.3.1 as appropriate.
- Review vendor advisory and release notes before deployment.
- Apply standard XSS defenses for custom WebUI changes or templates.
- Consider session invalidation after patching if exposure is suspected.
Validation and detection
- Inventory Rucio WebUI deployments and identify running versions.
- Confirm affected ranges are not present in production or staging.
- Verify upgrades match fixed releases: 35.8.3, 38.5.4, or 39.3.1.
- Review logs for unusual 500 error patterns and suspicious user-facing URLs.
- Confirm session cookie protections align with vendor and OWASP guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1004: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-25136 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N2.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/rucio/rucio/security/advisories/GHSA-h79m-5jjm-jm4qCVE reference · x_refsource_CONFIRM
- https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.htmlCVE reference · x_refsource_MISC
- https://github.com/rucio/rucio/releases/tag/35.8.3CVE reference · x_refsource_MISC
- https://github.com/rucio/rucio/releases/tag/38.5.4CVE reference · x_refsource_MISC
- https://github.com/rucio/rucio/releases/tag/39.3.1CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.