# REXML denial of service vulnerability

Advisory record · `GHSA-vmwr-mc7x-5vc3`

- **Identifiers:** `GHSA-vmwr-mc7x-5vc3` · `CVE-2024-43398`
- **State:** Confirmed
- **Severity:** CVSS 5.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-776](https://cwe.mitre.org/data/definitions/776.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 22 Aug 2024
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 22 Aug 2024, 16:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `rexml` (RubyGems): affected `<3.3.6`; fixed in `3.3.6`

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.012, the 68th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:16 UTC: First seen by agentprime
- 31 Oct 2026, 15:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-vmwr-mc7x-5vc3)

## Sources

- [GitHub Advisory Database: GHSA-vmwr-mc7x-5vc3](https://github.com/advisories/GHSA-vmwr-mc7x-5vc3)
- [OSV: GHSA-vmwr-mc7x-5vc3](https://osv.dev/vulnerability/GHSA-vmwr-mc7x-5vc3)
- <https://github.com/ruby/rexml/security/advisories/GHSA-vmwr-mc7x-5vc3>
- <https://nvd.nist.gov/vuln/detail/CVE-2024-43398>
- <https://github.com/ruby/rexml/commit/7cb5eaeb221c322b9912f724183294d8ce96bae3>
- <https://github.com/ruby/rexml>
- <https://github.com/ruby/rexml/releases/tag/v3.3.6>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rexml/CVE-2024-43398.yml>
- <https://lists.debian.org/debian-lts-announce/2025/01/msg00011.html>
- <https://security.netapp.com/advisory/ntap-20250103-0006>
- <https://www.ruby-lang.org/en/news/2024/08/22/dos-rexml-cve-2024-43398>

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-vmwr-mc7x-5vc3>, 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-vmwr-mc7x-5vc3/>. Everything for agents: <https://agentprime.io/llms.txt>.