Security readout for executives and security teams
Plain-English summary
Rucio WebUI versions before the fixed releases can store unsafe content in an Identity Name and later show it to other users. If a privileged attacker can set that value, JavaScript may run in a viewer’s browser. Business risk is account/session compromise or unauthorized actions within the Rucio WebUI.
Executive priority
Prioritize remediation for internet-accessible or broadly used Rucio WebUI deployments. The issue is not reported as actively exploited, but stored XSS can compromise user sessions and trust in a scientific data-management platform.
Technical view
CVE-2026-25735 is a stored XSS in Rucio WebUI Identity Name handling. Backend-persisted attacker-controlled input is rendered without proper output encoding. Affected ranges are <35.8.3, >=36.0.0rc1 <38.5.4, and >=39.0.0rc1 <39.3.1. CVSS 3.1 is 6.1 with high confidentiality and integrity impact, requiring high privileges and user interaction.
Likely exposure
Exposure is limited to organizations running Rucio WebUI in the listed affected version ranges. The CVSS vector indicates network reachability, high privileges required, and user interaction by someone viewing affected WebUI pages.
Exploitation context
The source bundle does not indicate known active exploitation, and KEV status is false. Practical abuse requires an attacker able to persist a malicious Identity Name, then a user viewing the affected WebUI content.
Researcher notes
Key constraints are PR:H and UI:R, with scope unchanged and no availability impact in the provided CVSS. Sources identify the vulnerable sink as WebUI rendering of Identity Name without proper output encoding. Avoid assuming affected integrations or authentication mechanisms beyond Rucio WebUI.
Mitigation direction
- Upgrade Rucio to 35.8.3, 38.5.4, or 39.3.1 as appropriate for your branch.
- Review the GitHub advisory and release notes for deployment-specific guidance.
- Apply secure output encoding practices consistent with OWASP XSS prevention guidance.
- Restrict administrative or identity-management permissions to trusted users.
Validation and detection
- Inventory Rucio deployments and confirm whether WebUI is enabled.
- Check installed Rucio versions against the affected ranges.
- Verify upgraded systems report 35.8.3, 38.5.4, 39.3.1, or later fixed versions.
- Review identity records for unexpected or suspicious display-name content.
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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-25735 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
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/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:H/UI:R/S:U/C:H/I:H/A:N0.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/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-8wpv-6x3f-3rm5CVE 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.
Sensitive Cookie Without 'HttpOnly' Flag
Sensitive Cookie Without 'HttpOnly' Flag represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.