# StringIO buffer overread vulnerability

Advisory record · `GHSA-v5h6-c2hv-hv3r`

- **Identifiers:** `GHSA-v5h6-c2hv-hv3r` · `CVE-2024-27280`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-120](https://cwe.mitre.org/data/definitions/120.html) · [CWE-126](https://cwe.mitre.org/data/definitions/126.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) · [CWE-126](https://agentprime.io/advisories/tag/cwe-126.md)
- **Published:** 25 Mar 2024
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 25 Mar 2024, 19:36 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

- `stringio` (RubyGems): affected `<3.0.1.1`; fixed in `3.0.1.1`

## 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:** 0.024, the 83rd percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:16 UTC: First seen by agentprime
- 31 Oct 2026, 15:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-v5h6-c2hv-hv3r)

## Sources

- [GitHub Advisory Database: GHSA-v5h6-c2hv-hv3r](https://github.com/advisories/GHSA-v5h6-c2hv-hv3r)
- [OSV: GHSA-v5h6-c2hv-hv3r](https://osv.dev/vulnerability/GHSA-v5h6-c2hv-hv3r)
- <https://nvd.nist.gov/vuln/detail/CVE-2024-27280>
- <https://github.com/ruby/stringio/commit/0e596524097706263d10900ca180898e4a8f5233>
- <https://github.com/ruby/stringio/commit/c58c5f54f1eab99665ea6a161d29ff6a7490afc8>
- <https://hackerone.com/reports/1399856>
- <https://github.com/ruby/stringio>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/stringio/CVE-2024-27280.yml>
- <https://lists.debian.org/debian-lts-announce/2024/09/msg00000.html>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/27LUWREIFTP3MQAW7QE4PJM4DPAQJWXF>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XYDHPHEZI7OQXTQKTDZHGZNPIJH7ZV5N>
- <https://security.netapp.com/advisory/ntap-20250502-0003>
- <https://www.ruby-lang.org/en/news/2024/03/21/buffer-overread-cve-2024-27280>
- <http://seclists.org/fulldisclosure/2025/Sep/53>

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-v5h6-c2hv-hv3r>, 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-v5h6-c2hv-hv3r/>. Everything for agents: <https://agentprime.io/llms.txt>.