# Nokogiri::XML::Schema trusts input by default, exposing risk of XXE vulnerability

Advisory record · `GHSA-vr8q-g5c7-m54m`

- **Identifiers:** `GHSA-vr8q-g5c7-m54m` · `CVE-2020-26247`
- **State:** Confirmed
- **Severity:** CVSS 2.6 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-611](https://cwe.mitre.org/data/definitions/611.html)
- **Tags:** [XML external entities (XXE)](https://agentprime.io/advisories/tag/xxe.md)
- **Published:** 30 Dec 2020
- **Updated:** 8 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 30 Dec 2020, 18:35 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `nokogiri` (RubyGems): affected `<1.11.0`; fixed in `1.11.0`

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.012, the 67th 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 30 Dec 2020. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-vr8q-g5c7-m54m](https://github.com/advisories/GHSA-vr8q-g5c7-m54m)
- [OSV: GHSA-vr8q-g5c7-m54m](https://osv.dev/vulnerability/GHSA-vr8q-g5c7-m54m)
- <https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-vr8q-g5c7-m54m>
- <https://nvd.nist.gov/vuln/detail/CVE-2020-26247>
- <https://github.com/sparklemotion/nokogiri/commit/9c87439d9afa14a365ff13e73adc809cb2c3d97b>
- <https://hackerone.com/reports/747489>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/nokogiri/CVE-2020-26247.yml>
- <https://github.com/sparklemotion/nokogiri>
- <https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md#v1110--2021-01-03>
- <https://github.com/sparklemotion/nokogiri/releases/tag/v1.11.0.rc4>
- <https://lists.debian.org/debian-lts-announce/2021/06/msg00007.html>
- <https://lists.debian.org/debian-lts-announce/2022/10/msg00018.html>
- <https://rubygems.org/gems/nokogiri>
- <https://security.gentoo.org/glsa/202208-29>

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-vr8q-g5c7-m54m>, 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-vr8q-g5c7-m54m/>. Everything for agents: <https://agentprime.io/llms.txt>.