CVE-2025-65200 LocalStack CVE debrief

Who should care

Defenders responsible for localstack instances should assess exposure and prioritize patching or mitigation. Defenders should verify the affected version of localstack and apply patches or mitigations to prevent exploitation. This issue requires defenders to review the CVE and assess the affected scope, severity, and vendor guidance.

Why it matters

CVE-2025-65200 is a vulnerability in localstack 4.9.2 that allows attackers to execute arbitrary code via crafted content hosted on a web-accessible URL, requiring defenders to verify the affected version and apply patches or mitigations.

• Potential code execution in the context of the Docker container
• Possible unauthorized access to sensitive data or systems
• Required verification of affected version and application of patches or mitigations

Technical summary

The vulnerability is caused by a lack of input validation in the _localstack/cloudformation/deploy endpoint, allowing attackers to execute arbitrary code via crafted content hosted on a web-accessible URL. This issue requires defenders to assess the affected version and apply patches or mitigations to prevent exploitation. The vulnerability allows attackers to execute arbitrary code in the context of the Docker container, and defenders should prioritize verifying the affected version and applying patches or mitigations.

Defensive priority

Defenders should prioritize verifying the affected version of localstack and applying patches or mitigations to prevent exploitation.

Recommended defensive actions

• Verify the version of localstack being used and apply patches or mitigations if necessary
• Restrict access to the _localstack/cloudformation/deploy endpoint
• Monitor for suspicious activity on the localstack instance
• 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 vulnerability is described in the CVE record and additional details are provided in the source references, including a GitHub pull request and a blog post. The CVE record provides source-provided CVE metadata, and the GitHub pull request addresses the vulnerability. Defenders should verify the affected version of localstack and apply patches or mitigations to prevent exploitation. The vulnerability allows attackers to execute arbitrary code via crafted content hosted on a web-accessible URL, and defenders should review the CVE and

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.