# XML Processing error in github.com/crewjam/saml

Advisory record · `GHSA-4hq8-gmxx-h6w9`

- **Identifiers:** `GHSA-4hq8-gmxx-h6w9` · `BIT-grafana-2020-27846` · `CVE-2020-27846` · `GO-2021-0058`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-115](https://cwe.mitre.org/data/definitions/115.html) · [CWE-287](https://cwe.mitre.org/data/definitions/287.html)
- **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md) · [CWE-115](https://agentprime.io/advisories/tag/cwe-115.md)
- **Published:** 23 Jun 2021
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 23 Jun 2021, 17:29 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

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

## Affected packages

- `github.com/crewjam/saml` (Go): affected `<0.4.3`; fixed in `0.4.3`

## 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

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.049, the 92nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:44 UTC: First seen by agentprime
- 31 Oct 2026, 14:44 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-4hq8-gmxx-h6w9)

## Sources

- [GitHub Advisory Database: GHSA-4hq8-gmxx-h6w9](https://github.com/advisories/GHSA-4hq8-gmxx-h6w9)
- [OSV: GHSA-4hq8-gmxx-h6w9](https://osv.dev/vulnerability/GHSA-4hq8-gmxx-h6w9)
- <https://github.com/crewjam/saml/security/advisories/GHSA-4hq8-gmxx-h6w9>
- <https://nvd.nist.gov/vuln/detail/CVE-2020-27846>
- <https://github.com/crewjam/saml/commit/da4f1a0612c0a8dd0452cf8b3c7a6518f6b4d053>
- <https://bugzilla.redhat.com/show_bug.cgi?id=1907670>
- <https://github.com/crewjam/saml>
- <https://grafana.com/blog/2020/12/17/grafana-6.7.5-7.2.3-and-7.3.6-released-with-important-security-fix-for-grafana-enterprise>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3YUTKIRWT6TWU7DS6GF3EOANVQBFQZYI>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ICP3YRY2VUCNCF2VFUSK77ZMRIC77FEM>
- <https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities>
- <https://pkg.go.dev/vuln/GO-2021-0058>
- <https://security.netapp.com/advisory/ntap-20210205-0002>

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-4hq8-gmxx-h6w9>, 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-4hq8-gmxx-h6w9/>. Everything for agents: <https://agentprime.io/llms.txt>.