# github.com/tidwall/gjson Vulnerable to REDoS attack

Advisory record · `GHSA-c9gm-7rfj-8w5h`

- **Identifiers:** `GHSA-c9gm-7rfj-8w5h` · `CVE-2021-42248` · `CVE-2021-42836` · `GHSA-ppj4-34rq-v8j9` · `GO-2021-0265`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html) · [CWE-697](https://cwe.mitre.org/data/definitions/697.html) · [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [CWE-697](https://agentprime.io/advisories/tag/cwe-697.md)
- **Published:** 25 Oct 2021
- **Updated:** 20 May 2024
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 25 Oct 2021, 19:43 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/tidwall/gjson` (Go): affected `<1.9.3`; fixed in `1.9.3`

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.024, the 84th percentile, on 6 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 25 Oct 2021. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-c9gm-7rfj-8w5h](https://github.com/advisories/GHSA-c9gm-7rfj-8w5h)
- [OSV: GHSA-c9gm-7rfj-8w5h](https://osv.dev/vulnerability/GHSA-c9gm-7rfj-8w5h)
- <https://nvd.nist.gov/vuln/detail/CVE-2021-42836>
- <https://github.com/tidwall/gjson/issues/236>
- <https://github.com/tidwall/gjson/issues/237>
- <https://github.com/tidwall/gjson/commit/590010fdac311cc8990ef5c97448d4fec8f29944>
- <https://github.com/tidwall/gjson/commit/77a57fda87dca6d0d7d4627d512a630f89a91c96>
- <https://github.com/tidwall/gjson>
- <https://github.com/tidwall/gjson/compare/v1.9.2...v1.9.3>
- <https://pkg.go.dev/vuln/GO-2021-0265>

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-c9gm-7rfj-8w5h>, 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-c9gm-7rfj-8w5h/>. Everything for agents: <https://agentprime.io/llms.txt>.