critical CVSS 9.8

CVE-2026-33229·Python vulnerability

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Prior to 17.4.8 and 17.10.1, an improperly protected scripting API allows any user with script right to bypass the sandboxing of the Velocity scripting API and execute, e.g., arbitrary Python scripts, allowing full access to the XWiki instance and thereby compromising the confidentiality, integrity and availability of the whole instance. Note that script right already constitutes a high level of access that we don't recommend giving to untrusted users. This vulnerability is fixed in 17.4.8 and 17.10.1.

Severity: critical
Software: Python
Fixed in: 17.10.1
Published: 2026-04-08

Affected versions

From: 17.5.0

Until: 17.10.1

Fixed in: 17.10.1

How to fix this CVE

Update XWiki Platform immediately to version 17.10.1 or later to patch the Velocity scripting sandbox bypass vulnerability. This critical flaw allows users with script execution rights to break out of sandboxing restrictions and run arbitrary code with full instance access. Audit all users currently granted script rights and restrict this privilege to trusted administrators only.

sudo dnf update python3

Defensia detects this vulnerability

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch.

Implement strict rate limiting and IP whitelisting on XWiki administrative endpoints. Block POST requests to /xwiki/bin/edit/ containing Velocity template injection patterns such as #set, #foreach, or $xwiki.* macro calls from non-administrative subnets. Monitor for unusual script execution API calls.

How to check if you are affected

Check XWiki Platform version: curl -s http://localhost:8080/xwiki/bin/view/Main/ | grep -i 'xwiki.*version' or check xwiki.properties for environment variable
Identify users with script execution rights: Query the XWiki database for users in 'XWiki.XWikiAdminGroup' or with explicit 'script' permission via the admin console
Search XWiki logs for suspicious Velocity/Python execution: grep -r 'Velocity.*eval\|Python.*exec\|groovy.*Runtime' /var/log/xwiki/ or check database for abnormal script execution in audit logs
Verify patch installation: curl -s http://localhost:8080/xwiki/bin/view/Main/ and confirm version is 17.10.1 or higher, or check xwiki-core JAR manifest

FAQ

What is CVE-2026-33229?

CVE-2026-33229 is a critical sandbox bypass vulnerability in XWiki Platform versions 17.5.0 through 17.10.0 where users with script execution rights can circumvent Velocity API protections and execute arbitrary Python code, gaining complete control over the XWiki instance.

Is CVE-2026-33229 being actively exploited?

No, CVE-2026-33229 is not currently listed on the CISA Known Exploited Vulnerabilities catalog and no public exploits are available, though the attack surface is limited to authenticated users with existing script rights.

What versions of XWiki Platform are affected by CVE-2026-33229?

XWiki Platform versions 17.5.0 through 17.10.0 are vulnerable; versions 17.4.8 and 17.10.1 or later contain the fix.

How do I check if my XWiki instance is vulnerable to CVE-2026-33229?

Access your XWiki admin panel and verify the platform version; versions between 17.5.0 and 17.10.0 are vulnerable. You can also run: curl -I http://your-xwiki-server/xwiki/ and check the X-XWiki-Version header if enabled.

Does Defensia detect CVE-2026-33229?

Yes — Defensia's CVE advisory scanner analyzes your XWiki Platform deployment version and compares it against the NVD vulnerability database. If a vulnerable version is detected, CVE-2026-33229 will appear in your security dashboard with automated remediation guidance.

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References

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