# Cross-site scripting in the comments bundle (see GHSA-628f-v4f6-p37r)

Advisory record · `PKSA-3fqv-nq39-s3wg`

- **Identifiers:** `PKSA-3fqv-nq39-s3wg` · `CVE-2026-107845`
- **State:** Confirmed
- **Severity:** CVSS 9.3 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-79](https://cwe.mitre.org/data/definitions/79.html) · [CWE-116](https://cwe.mitre.org/data/definitions/116.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md) · [CWE-116](https://agentprime.io/advisories/tag/cwe-116.md)
- **Published:** 25 Aug 2026
- **Updated:** 25 Aug 2026
- **Reviewed by a person:** No

Published by Packagist at 25 Aug 2026, 06:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.3: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `contao/contao` (Packagist): affected `>=4.0.0, <5.3.50 || >=5.4.0, <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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0028, the 20th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 25 Aug 2026, 06:40 UTC: [Confirmed by Packagist](https://contao.org/en/security-advisories/cross-site-scripting-in-the-comments-bundle)

## Sources

- [OSV: PKSA-3fqv-nq39-s3wg](https://osv.dev/vulnerability/PKSA-3fqv-nq39-s3wg)
- <https://contao.org/en/security-advisories/cross-site-scripting-in-the-comments-bundle>

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/PKSA-3fqv-nq39-s3wg>, 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/PKSA-3fqv-nq39-s3wg/>. Everything for agents: <https://agentprime.io/llms.txt>.