# RubyGems Improper Verification of Cryptographic Signature vulnerability

Advisory record · `GHSA-mc6j-h948-v2p6`

- **Identifiers:** `GHSA-mc6j-h948-v2p6` · `CVE-2018-1000076`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-347](https://cwe.mitre.org/data/definitions/347.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 14 May 2022
- **Updated:** 11 Mar 2024
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 14 May 2022, 01:01 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

- `rubygems-update` (RubyGems): affected `>=2.2.0, <2.7.6`; fixed in `2.7.6`
- `org.jruby:jruby-stdlib` (Maven): affected `<9.1.16.0`; fixed in `9.1.16.0`

## 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

- 9.8 Critical, CVSS 3.0: `CVSS:3.0/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:** 0.029, the 87th 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 14 May 2022. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-mc6j-h948-v2p6](https://github.com/advisories/GHSA-mc6j-h948-v2p6)
- [OSV: GHSA-mc6j-h948-v2p6](https://osv.dev/vulnerability/GHSA-mc6j-h948-v2p6)
- <https://nvd.nist.gov/vuln/detail/CVE-2018-1000076>
- <https://github.com/jruby/jruby/commit/0b06b48ab4432237ce5fc1bef47f2c6bcf7843f7>
- <https://github.com/rubygems/rubygems/commit/f5042b879259b1f1ce95a0c5082622c646376693>
- <https://www.debian.org/security/2018/dsa-4259>
- <https://www.debian.org/security/2018/dsa-4219>
- <https://usn.ubuntu.com/3621-1>
- <https://lists.debian.org/debian-lts-announce/2019/05/msg00028.html>
- <https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html>
- <https://lists.debian.org/debian-lts-announce/2018/04/msg00023.html>
- <https://lists.debian.org/debian-lts-announce/2018/04/msg00001.html>
- <https://lists.debian.org/debian-lts-announce/2018/04/msg00000.html>
- <https://github.com/rubygems/rubygems>

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-mc6j-h948-v2p6>, 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-mc6j-h948-v2p6/>. Everything for agents: <https://agentprime.io/llms.txt>.