CVE-2026-82273Public exploitNetwork attack vector

Cross-tenant data disclosure via skipped ownership checks

Published Aug 28, 2026 · Updated Aug 28, 2026

Authentication bypass in Mastra through 1.63.0 allows remote authenticated users to read other owners' conversation histories via the Memory API. When mapUserToResourceId is absent, getEffectiveResourceId returns undefined, so validateThreadOwnership skips comparison and list filtering. Any authenticated account in such a multi-user deployment can enumerate all threads and read their metadata, messages, and working-memory state.

CVSS severity7.1
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Mastra through 1.63.0 allows remote authenticated users to read other owners' conversation histories via the Memory API. When mapUserToResourceId is absent, getEffectiveResourceId returns undefined, so validateThreadOwnership skips comparison and list filtering. Any authenticated account in such a multi-user deployment can enumerate all threads and read their metadata, messages, and working-memory state.

The record

CVE
CVE-2026-82273
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
Mastra
Product
Mastra
Classifications
CWE-862, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.63.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mastra · Mastraversion=0 <=1.63.0

Published CVSS scores

7.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
6.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1213Data from Information Repositories

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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