CVE-2026-82273 mastra-ai CVE debrief

Who should care

Defenders responsible for Mastra deployments should assess the potential impact of this vulnerability on their systems and data. They should verify the presence of this vulnerability and implement authentication and authorization controls to prevent exploitation.

Why it matters

CVE-2026-82273 is a high-severity vulnerability in Mastra that allows authenticated attackers to bypass authentication and potentially read sensitive data. Defenders should prioritize verifying the presence of this vulnerability in their Mastra deployments and assess the potential impact on their systems.

• Authenticated attackers can enumerate all threads via GET /api/memory/threads
• Potential reading of conversation history and metadata of other resource owners
• Verification of Mastra deployments for vulnerability presence is necessary
• Implementation of authentication and authorization controls to prevent exploitation is required

Technical summary

The vulnerability is caused by a missing authentication check in the memory API thread ownership validation when the mapUserToResourceId callback is omitted from configuration. This allows authenticated attackers to enumerate all threads and potentially read conversation history and metadata of other resource owners. The issue arises from inadequate authentication mechanisms in the Mastra product, specifically in how it handles thread ownership validation. This could lead to unauthorized access to sensitive information.

Defensive priority

Defenders should prioritize verifying the presence of this vulnerability in their Mastra deployments and assess the potential impact on their systems.

Recommended defensive actions

• Verify the presence of this vulnerability in Mastra deployments
• Assess the potential impact on systems and data
• Implement authentication and authorization controls to prevent exploitation
• 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 entry provide details about the vulnerability, but the vendor and affected versions are not clearly identified. Further verification is needed to determine the scope of the vulnerability.

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.