# Better Auth has an account takeover issue via OAuth auto-link to unverified pre-registered email

Advisory record · `GHSA-g38m-r43w-p2q7`

- **Identifiers:** `GHSA-g38m-r43w-p2q7` · `CVE-2026-53516`
- **State:** Confirmed
- **Severity:** CVSS 8.3 High
- **Critical:** No
- **Weakness (CWE):** [CWE-287](https://cwe.mitre.org/data/definitions/287.html) · [CWE-345](https://cwe.mitre.org/data/definitions/345.html)
- **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md) · [CWE-345](https://agentprime.io/advisories/tag/cwe-345.md)
- **Published:** 7 Jul 2026
- **Updated:** 20 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 Jul 2026, 20:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `better-auth` (npm): affected `<1.6.11`; fixed in `1.6.11`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.3 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0029, the 21st percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 7 Jul 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-g38m-r43w-p2q7](https://github.com/advisories/GHSA-g38m-r43w-p2q7)
- [OSV: GHSA-g38m-r43w-p2q7](https://osv.dev/vulnerability/GHSA-g38m-r43w-p2q7)
- <https://github.com/better-auth/better-auth/security/advisories/GHSA-g38m-r43w-p2q7>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-53516>
- <https://github.com/better-auth/better-auth/pull/9578>
- <https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cc6ab9fb563>
- <https://github.com/better-auth/better-auth>
- <https://github.com/better-auth/better-auth/releases/tag/v1.6.11>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-g38m-r43w-p2q7>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-g38m-r43w-p2q7/>. Everything for agents: <https://agentprime.io/llms.txt>.