CVE-2026-40104 XWiki's REST APIs can list all pages/spaces, leading to unavailability
Attackers can cause denial of service on large XWiki instances by triggering resource exhaustion via REST API endpoints that lack query limits.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40104?
CVE-2026-40104 is a medium-severity denial of service vulnerability in Xwiki Xwiki, published on 15 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Versions 1.8-rc-1, 17.0.0-rc-1 and 17.5.0-rc-1 and prior include a resource exhaustion vulnerability in REST API endpoints such as /xwiki/rest/wikis/xwiki/spaces/AnnotationCode/pages/AnnotationConfig/objects/AnnotationCode.AnnotationConfig/0/properties, which list all available pages as part of the metadata for database list properties without applying query limits. On large wikis, this can exhaust available server resources. This issue has been patched in versions 16.10.16, 17.4.8 and 17.10.1.
Weakness: CWE-770
Which versions are affected by CVE-2026-40104?
12 open source packages ship an affected version, including org.xwiki.platform:xwiki-platform-legacy-oldcore and org.xwiki.platform:xwiki-platform-oldcore. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 1.8-rc-1 | 16.10.16 |
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 1.8-rc-1 | 16.10.16 |
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 17.0.0-rc-1 | 17.4.8 |
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 17.0.0-rc-1 | 17.4.8 |
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 17.5.0-rc-1 | 17.10.1 |
org.xwiki.platform:xwiki-platform-legacy-oldcore Maven | From 17.5.0-rc-1 | 17.10.1 |
6 more packages
org.xwiki.platform:xwiki-platform-oldcore Maven | From 1.8-rc-1 | 16.10.16 |
org.xwiki.platform:xwiki-platform-oldcore Maven | From 1.8-rc-1 | 16.10.16 |
org.xwiki.platform:xwiki-platform-oldcore Maven | From 17.0.0-rc-1 | 17.4.8 |
org.xwiki.platform:xwiki-platform-oldcore Maven | From 17.0.0-rc-1 | 17.4.8 |
org.xwiki.platform:xwiki-platform-oldcore Maven | From 17.5.0-rc-1 | 17.10.1 |
org.xwiki.platform:xwiki-platform-oldcore Maven | From 17.5.0-rc-1 | 17.10.1 |
Products include Xwiki Xwiki.
How do I fix CVE-2026-40104?
Upgrade org.xwiki.platform:xwiki-platform-legacy-oldcore to a fixed version for your release line: 16.10.16, 17.4.8 or 17.10.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-40104 being exploited?
There is no known exploitation of CVE-2026-40104 in the wild and no public exploit code.
Other vulnerabilities in Xwiki Xwiki
- CVE-2025-24893 XWiki Platform Eval Injection
- CVE-2025-53836 XWiki Rendering is vulnerable to RCE attacks when processing nested macros
- CVE-2024-55662 XWiki allows remote code execution through the extension sheet
- CVE-2024-55877 XWiki allows remote code execution from account through macro descriptions and XWiki.XWikiSyntaxMacrosList
- CVE-2024-37901 XWiki Platform vulnerable to remote code execution from account via SearchSuggestConfigSheet
Sources
Also known as GHSA-mrqg-xmgm-rc5g.