# Contao: The registration module re-sends activation mails

Advisory record · `GHSA-mfxh-vp55-7gc6`

- **Identifiers:** `GHSA-mfxh-vp55-7gc6` · `CVE-2026-107843` · `PKSA-s71c-hg32-kv3f`
- **State:** Confirmed
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-204](https://cwe.mitre.org/data/definitions/204.html) · [CWE-770](https://cwe.mitre.org/data/definitions/770.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [CWE-204](https://agentprime.io/advisories/tag/cwe-204.md)
- **Published:** 9 Oct 2026
- **Updated:** 9 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 9 Oct 2026, 20:54 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `contao/core-bundle` (Packagist): affected `>=4.1.0, <5.3.50 || >=5.4.0-RC1, <5.7.12`; fixed in `5.3.50`, `5.7.12`

## 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

- 5.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0027, the 19th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:54 UTC: First seen by agentprime
- 31 Oct 2026, 13:54 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-mfxh-vp55-7gc6)

## Sources

- [GitHub Advisory Database: GHSA-mfxh-vp55-7gc6](https://github.com/advisories/GHSA-mfxh-vp55-7gc6)
- [OSV: GHSA-mfxh-vp55-7gc6](https://osv.dev/vulnerability/GHSA-mfxh-vp55-7gc6)
- <https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6>
- <https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74b>
- <https://github.com/contao/contao>
- <https://github.com/contao/contao/releases/tag/5.3.50>
- <https://github.com/contao/contao/releases/tag/5.7.12>

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-mfxh-vp55-7gc6>, 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-mfxh-vp55-7gc6/>. Everything for agents: <https://agentprime.io/llms.txt>.