Is CVE-2026-40104 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-40104 being exploited in the wild.

How severe is CVE-2026-40104?

High severity, with a CVSS score of 8.2, published 15 April 2026.

Which products and versions are affected?

org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16; org.xwiki.platform:xwiki-platform-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16.

Am I affected by CVE-2026-40104?

Check whether you run org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven), org.xwiki.platform:xwiki-platform-oldcore (Maven) or Xwiki at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-40104: XWiki's REST APIs can list all pages/spaces, leading to unavailability

CVE-2026-40104 · Severity: high · CVSS 8.2 · Published 2026-04-15

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.

Technologies: org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven), org.xwiki.platform:xwiki-platform-oldcore (Maven). Vendors: Maven, Xwiki.

Quick answers

Is CVE-2026-40104 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-40104 being exploited in the wild.
How severe is CVE-2026-40104?: High severity, with a CVSS score of 8.2, published 15 April 2026.
Which products and versions are affected?: org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16; org.xwiki.platform:xwiki-platform-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16.
Is there a fix for CVE-2026-40104?: Yes. org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven): upgrade to 16.10.16 or later; org.xwiki.platform:xwiki-platform-oldcore (Maven): upgrade to 16.10.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-40104?: Check whether you run org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven), org.xwiki.platform:xwiki-platform-oldcore (Maven) or Xwiki at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven): upgrade to 16.10.16 or later

# set org.xwiki.platform:xwiki-platform-legacy-oldcore to 16.10.16 in your pom.xml or build.gradle

org.xwiki.platform:xwiki-platform-oldcore (Maven): upgrade to 16.10.16 or later

# set org.xwiki.platform:xwiki-platform-oldcore to 16.10.16 in your pom.xml or build.gradle

Affected products

org.xwiki.platform:xwiki-platform-legacy-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16
org.xwiki.platform:xwiki-platform-oldcore (Maven) ECOSYSTEM:introduced=1.8-rc-1,fixed=16.10.16
Xwiki

Identifiers

CVE-2026-40104
GHSA-mrqg-xmgm-rc5g

References

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