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PatchSiren cyber security CVE debrief

CVE-2026-40104 xwiki CVE debrief

CVE-2026-40104 is a resource exhaustion vulnerability in XWiki Platform's REST API endpoints. The issue affects versions 1.8-rc-1, 17.0.0-rc-1, and 17.5.0-rc-1 and prior. An attacker can exploit this vulnerability by listing all available pages as part of the metadata for database list properties without applying query limits, leading to server resource exhaustion on large wikis. This issue has been patched in versions 16.10.16, 17.4.8, and 17.10.1.

Vendor
xwiki
Product
org.xwiki.platform:xwiki-platform-oldcore
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-15
Original CVE updated
2026-10-26
Advisory published
2026-04-15
Advisory updated
2026-10-26

Who should care

Defenders responsible for XWiki Platform instances, especially those with large wikis, should assess exposure and prioritize patching to prevent potential server resource exhaustion.

Why it matters

CVE-2026-40104 is a resource exhaustion vulnerability in XWiki Platform's REST API endpoints. Defenders responsible for XWiki Platform instances, especially those with large wikis, should assess exposure and prioritize patching to prevent potential server resource exhaustion.

  • Server resource exhaustion may occur on large wikis due to unlimitted metadata queries
  • Defenders should verify affected versions and patch status
  • Remediation priority is high for large wikis

Technical summary

The vulnerability affects XWiki Platform versions 1.8-rc-1, 17.0.0-rc-1, and 17.5.0-rc-1 and prior. The REST API endpoints, such as /xwiki/rest/wikis/xwiki/spaces/AnnotationCode/pages/AnnotationConfig/objects/AnnotationCode.AnnotationConfig/0/properties, list all available pages as part of the metadata for database list properties without applying query limits, leading to server resource exhaustion on large wikis.

Defensive priority

Defenders should prioritize patching vulnerable XWiki Platform instances, especially for large wikis, to prevent potential server resource exhaustion.

Recommended defensive actions

  • Patch vulnerable XWiki Platform instances to prevent server resource exhaustion
  • Review and limit metadata queries on large wikis
  • Monitor server resources for potential exhaustion
  • Verify affected XWiki Platform instances exist in managed environments
  • Review compensating controls for exposed systems while remediation is scheduled
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, affected versions, and patched versions. However, the corpus does not establish evidence of exploitation or specific attack scenarios.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40104 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40104

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-40104 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40104

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.