# Authorization bypass in github.com/dgrijalva/jwt-go

Advisory record · `GHSA-w73w-5m7g-f7qc`

- **Identifiers:** `GHSA-w73w-5m7g-f7qc` · `CVE-2020-26160` · `GO-2020-0017` · `SNYK-GOLANG-GITHUBCOMDGRIJALVAJWTGO-596515`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-287](https://cwe.mitre.org/data/definitions/287.html) · [CWE-755](https://cwe.mitre.org/data/definitions/755.html)
- **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md) · [CWE-755](https://agentprime.io/advisories/tag/cwe-755.md)
- **Published:** 18 May 2021
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 18 May 2021, 21:08 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/dgrijalva/jwt-go` (Go): affected `>=0.0.0-20150717181359-44718f8a89b0, <=3.2.0`; no fixed version yet
- `github.com/dgrijalva/jwt-go/v4` (Go): affected `<4.0.0-preview1`; fixed in `4.0.0-preview1`

## 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

- 7.5 High, CVSS 3.1: `CVSS:3.1/AC:L/AV:N/A:N/C:H/I:N/PR:N/S:U/UI:N`, from CNA (mitre)

- **CISA KEV:** Not listed.
- **EPSS:** 0.022, the 82nd percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:46 UTC: First seen by agentprime
- 31 Oct 2026, 14:46 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-w73w-5m7g-f7qc)

## Sources

- [GitHub Advisory Database: GHSA-w73w-5m7g-f7qc](https://github.com/advisories/GHSA-w73w-5m7g-f7qc)
- [OSV: GHSA-w73w-5m7g-f7qc](https://osv.dev/vulnerability/GHSA-w73w-5m7g-f7qc)
- <https://nvd.nist.gov/vuln/detail/CVE-2020-26160>
- <https://github.com/dgrijalva/jwt-go/issues/422>
- <https://github.com/dgrijalva/jwt-go/issues/462>
- <https://github.com/dgrijalva/jwt-go/pull/426>
- <https://github.com/dgrijalva/jwt-go/commit/ec0a89a131e3e8567adcb21254a5cd20a70ea4ab>
- <https://github.com/dgrijalva/jwt-go>
- <https://pkg.go.dev/vuln/GO-2020-0017>
- <https://snyk.io/vuln/SNYK-GOLANG-GITHUBCOMDGRIJALVAJWTGO-596515>

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-w73w-5m7g-f7qc>, 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-w73w-5m7g-f7qc/>. Everything for agents: <https://agentprime.io/llms.txt>.