# CVE-2026-82273: Mastra Memory API Thread Ownership Check Is a No-op When mapUserToResourceId Is Unset

> Authenticated attackers can read other users' conversation history if the mapUserToResourceId callback is omitted from the Mastra memory API configuration.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Aug 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-q48c-g8g8-2xq8

## What is CVE-2026-82273?

CVE-2026-82273 is a high-severity missing authorization vulnerability in mastra-ai mastra, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-82273?


## How do I fix CVE-2026-82273?

No fix has been published for CVE-2026-82273 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82273 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82273 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82273 and fix it if it is affected.

What it is: CVE-2026-82273 is a high-severity missing authorization vulnerability in mastra-ai mastra, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82273 exists.

Affected product: mastra-ai mastra. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82273/ (Markdown: https://insights.sbomify.com/CVE-2026-82273/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82273
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82273
- OSV: https://osv.dev/vulnerability/CVE-2026-82273

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82273/
Summaries are generated and may contain mistakes; the official description above is the record.