CVE-2026-55496 cloudreve CVE debrief

Who should care

Defenders responsible for Cloudreve deployments should assess exposure and prioritize upgrading to version 4.17.0 or later. Security teams and vulnerability management teams should review the official advisory and verify exposure in their environments. Operators and administrators of Cloudreve should also be aware of the potential risks and take necessary actions to mitigate them. Security teams should monitor for potential enumeration and upgrade to the 4

Why it matters

CVE-2026-55496 allows enumeration of email addresses and profile metadata for inactive or banned accounts in Cloudreve deployments prior to version 4.17.0. Defenders should verify exposure and prioritize upgrading.

• Enumeration of email addresses and profile metadata for inactive or banned accounts is possible.
• Verification of exposure and remediation priority is required.
• Defenders should monitor for potential enumeration and upgrade to version 4.17.0 or later.

Technical summary

CVE-2026-55496 affects Cloudreve, a self-hosted file management and sharing system, prior to version 4.17.0. The vulnerability allows any logged-in user to enumerate email addresses and profile metadata for inactive or banned accounts due to improper filtering in the SearchActive method and inadequate serialization of search results. This issue is fixed in version 4.17.0. Defenders should prioritize verifying exposure and upgrading to version 4.17.0 or later to mitigate potential risks. The vulnerability is related to insufficient predicate addition in search functionality and improper result serialization.

Defensive priority

Defenders should prioritize verifying exposure and upgrading to version 4.17.0 or later.

Recommended defensive actions

• Verify exposure by checking if the system is using a version prior to 4.17.0.
• Upgrade to version 4.17.0 or later.
• Monitor for potential enumeration of email addresses and profile metadata.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and NVD detail page provide information on the vulnerability. The CVE Program record and NVD vulnerability detail are available for reference. Evidence limits are based on CVE and NVD records. Affected scope and severity are detailed in the official advisory. Defenders should verify exposure and prioritize remediation based on the official guidance.

Sources and 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.