# Subrion CMS vulnerable to Cross-site Scripting

Advisory record · `GHSA-wrcg-234w-hfhq`

- **Identifiers:** `GHSA-wrcg-234w-hfhq` · `CVE-2026-12202` · `PKSA-9dbm-kft4-ck43`
- **State:** Confirmed
- **Severity:** CVSS 4.8 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-79](https://cwe.mitre.org/data/definitions/79.html) · [CWE-94](https://cwe.mitre.org/data/definitions/94.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md) · [Code injection](https://agentprime.io/advisories/tag/code-injection.md)
- **Published:** 15 Jun 2026
- **Updated:** 26 Aug 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 15 Jun 2026, 03:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `intelliants/subrion` (Packagist): affected `<=4.0.3`; no fixed version yet

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Subrion CMS (intelliants/subrion) versions up to and including 4.0.3 are vulnerable to cross-site scripting through the CSS class name argument of an unspecified function in the Blocks endpoint. A remote attacker can exploit this, and a public exploit exists. The source lists no fixed version and the vendor did not respond to disclosure, so no fix is listed.

Written 3 Nov 2026.

## 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

- 4.8 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P`, from CNA (VulDB)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0021, the 11th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:24 UTC: First seen by agentprime
- 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-wrcg-234w-hfhq)

## Sources

- [GitHub Advisory Database: GHSA-wrcg-234w-hfhq](https://github.com/advisories/GHSA-wrcg-234w-hfhq)
- [OSV: GHSA-wrcg-234w-hfhq](https://osv.dev/vulnerability/GHSA-wrcg-234w-hfhq)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-12202>
- <https://github.com/intelliants/subrion>
- <https://hackmd.io/@noka/B1sue5Xkzl>
- <https://karinagante.github.io/cve-2026-12202>
- <https://karinagante.github.io/cve-2026-12202/#proof-of-concept-poc>
- <https://vuldb.com/cve/CVE-2026-12202>
- <https://vuldb.com/submit/830013>
- <https://vuldb.com/vuln/370845>
- <https://vuldb.com/vuln/370845/cti>

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-wrcg-234w-hfhq>, 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-wrcg-234w-hfhq/>. Everything for agents: <https://agentprime.io/llms.txt>.