Security readout for executives and security teams
Plain-English summary
Rucio WebUI has a stored XSS flaw in its Custom Rules function. A user with rule-writing access could save malicious content that later runs in another user’s browser when viewed. Business risk is account/session compromise and unauthorized actions inside Rucio. Fixed releases are available.
Executive priority
Treat as a high-priority application security update for Rucio environments. It is not confirmed exploited, but the flaw can compromise user sessions and actions in a scientific data-management platform. Prioritize exposed WebUI deployments and environments with broad Custom Rules access.
Technical view
CVE-2026-25733 affects rucio versions before 35.8.3, 38.5.4, and 39.3.1. Backend-persisted attacker-controlled Custom Rules input is rendered by the WebUI without proper output encoding. CVSS is 7.3, network exploitable, low complexity, requires low privileges and user interaction. CWE mappings include CWE-79 and CWE-1004.
Likely exposure
Organizations running Rucio WebUI with affected versions and users able to create or modify Custom Rules are exposed. Risk is higher where many operators or scientists use the WebUI and session cookies authorize sensitive data-management actions.
Exploitation context
The source bundle does not indicate active exploitation, and KEV status is false. Exploitation requires a privileged-enough user to persist malicious input and another user to view the affected WebUI page. Impact may include session token theft or unauthorized actions within the WebUI context.
Researcher notes
The advisory describes stored XSS via persisted Custom Rules input rendered without encoding. Do not assume broader Rucio components are affected beyond the stated WebUI function. Validate against affected version ranges and fixed release tags. Evidence for exploit-in-the-wild is absent in the provided sources.
Mitigation direction
- Upgrade Rucio to 35.8.3, 38.5.4, or 39.3.1 as applicable.
- Review the GitHub security advisory for version-specific remediation details.
- For maintained forks, apply contextual output encoding consistent with OWASP XSS guidance.
- Until upgraded, tightly review who can use Custom Rules in the WebUI.
Validation and detection
- Inventory Rucio deployments and record exact version branches.
- Confirm WebUI exposure and whether Custom Rules are enabled or used.
- Verify installed versions are not in the affected version ranges.
- Review recent Custom Rules entries for unexpected script-like content.
- After upgrade, confirm the deployed version matches a fixed release.
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-2026-25733 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
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/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:L/UI:R/S:U/C:H/I:H/A:N2.15.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:N/AC:L/PR:L/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-rwj9-7j48-9f7qCVE 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.