Auth bypass in Mastra-Ai Mastra
CVE-2026-82273
Mastra through 1.63.0 contains an authentication bypass vulnerability in the memory API thread ownership validation when mapUserToResourceId callback is omitted from configuration. Authenticated attackers can enumerate all threads via GET /api/memory/threads and read conversation history and metadata of other resource owners.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/mastra-ai/mastra/issues/18911 (issue-tracking)
- github.com/mastra-ai/mastra (product)
- github.com/mastra-ai/mastra/blob/b7e66f0c478a227985e0062794ef058c3714fabf/packa… (technical-description)
- www.vulncheck.com/advisories/mastra-memory-api-thread-ownership-check-is-a-no-o… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-82273?
- CVE-2026-82273 is a medium-severity vulnerability in Mastra-Ai Mastra, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-08-28.
- How severe is CVE-2026-82273?
- Medium severity. CVSS v3 base score is 6.5 out of 10.