CVE-2026-55497 cloudreve CVE debrief

Who should care

Cloudreve administrators and users with upload privileges should be aware of this vulnerability and take steps to mitigate it by updating to version 4.17.0 or later. Affected operators and security teams should review the official advisory and CVE record to validate affected scope and severity. Vulnerability management and platform security teams should prioritize updates and compensating controls for exposed systems while remediation is scheduled and verified. Monitoring and detection teams should check relevant logs for exposed assets that need extra review. Asset inventory management should track exceptions and retest remediated assets, closing the item only after evidence is documented. Limited source detail is available, so defenders should verify affected scope and severity with official advisories and track exceptions and retest remediated assets to ensure completeness of mitigation efforts across the environment. This vulnerability could impact operators with Cloudreve deployments, particularly those with low-privileged users who can upload images. Security teams should review compensating controls for exposed systems while remediation is scheduled and verified, and monitor for suspicious image upload activity. Vulnerability management teams should prioritize updates and compensating controls for exposed systems, and asset inventory management should track exceptions and retest remediated assets to ensure completeness of mitigation efforts across the environment. Limited source detail is available, so defenders should verify affected scope and severity with official advisories and track exceptions and retest remediated assets to ensure completeness of mitigation efforts across the environment. Security teams should review compensating controls for exposed systems while remediation is scheduled and verified, and monitor for suspicious image upload activity. Vulnerability management teams should prioritize updates and compensating controls for exposed systems, and asset inventory management should track exceptions and retest remediated assets to ensure completeness of mitigation efforts across the environment. Limited source detail is available, so Defders

Technical summary

CVE-2026-55497 is a denial-of-service vulnerability in Cloudreve versions prior to 4.17.0. An authenticated user can submit a crafted image that causes an out-of-memory condition, terminating the Cloudreve process. The vulnerability is due to the built-in thumbnail and avatar image decoders limiting compressed file size but not decoded pixel dimensions. This issue can be mitigated by updating to version 4.17.0 or later.

Defensive priority

Authenticated users with low privileges can cause a denial-of-service condition by submitting crafted images, requiring updates to Cloudreve to 4.17.0 or later.

Recommended defensive actions

• Update Cloudreve to version 4.17.0 or later
• Restrict image uploads to trusted users
• Monitor Cloudreve logs for suspicious image upload activity
• Implement compensating controls to detect and prevent potential attacks
• Review the official advisory and CVE record to validate affected scope and severity
• Track exceptions and retest remediated assets to ensure completeness of mitigation efforts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in Cloudreve versions prior to 4.17.0, where an authenticated user can submit a crafted image to cause an out-of-memory condition, terminating the Cloudreve process. Evidence is based on official CVE and NVD records, as well as vendor advisory information from GitHub. Limited source detail is available, so defenders should verify affected scope and severity with official advisories.

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.