# Sisimai Inefficient Regular Expression Complexity vulnerability

Advisory record · `GHSA-vm74-j4wq-82xj`

- **Identifiers:** `GHSA-vm74-j4wq-82xj` · `CVE-2022-4891`
- **State:** Confirmed
- **Severity:** CVSS 3.5 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 17 Jan 2023
- **Updated:** 22 Feb 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 17 Jan 2023, 21:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `sisimai` (RubyGems): affected `<4.25.14p12`; fixed in `4.25.14p12`

## 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

- 3.5 Low, CVSS 3.1: `CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`, from CNA (VulDB)

- **CISA KEV:** Not listed.
- **EPSS:** 0.014, the 72nd percentile, on 7 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 17 Jan 2023. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-vm74-j4wq-82xj](https://github.com/advisories/GHSA-vm74-j4wq-82xj)
- [OSV: GHSA-vm74-j4wq-82xj](https://osv.dev/vulnerability/GHSA-vm74-j4wq-82xj)
- <https://nvd.nist.gov/vuln/detail/CVE-2022-4891>
- <https://github.com/sisimai/rb-sisimai/pull/244>
- <https://github.com/sisimai/rb-sisimai/commit/51fe2e6521c9c02b421b383943dc9e4bbbe65d4e>
- <https://gist.githubusercontent.com/gmcabrita/e5dc0332473fc2e3a7a407434c8d21c7/raw/00b12035e5e1b685469f143b94301a50306376ba/example.html>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/sisimai/CVE-2022-4891.yml>
- <https://github.com/sisimai/rb-sisimai>
- <https://github.com/sisimai/rb-sisimai/releases/tag/v4.25.14p12>
- <https://vuldb.com/?ctiid.218452>
- <https://vuldb.com/?id.218452>

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-vm74-j4wq-82xj>, 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-vm74-j4wq-82xj/>. Everything for agents: <https://agentprime.io/llms.txt>.