---
title: "CVE-2024-27280: StringIO buffer overread vulnerability"
url: https://erroneo.us/security/cve/CVE-2024-27280/
description: "CVE-2024-27280 (stringio (RubyGems)): A buffer-overread issue was discovered in StringIO 3.0.1, as distributed in Ruby 3.0.x through 3.0.6 and 3.1.x through…"
type: vulnerability-record
section: "Security Digest"
date_published: 2024-05-08
date_modified: 2025-11-04
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2024-27280"
kev: false
cvss: 9.3
epss: 0.02364
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2024-27280: StringIO buffer overread vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 2.4% , percentile 84: FIRST’s model estimates a 2.4% chance of exploitation activity in the next 30 days, higher than 84% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes stringio (RubyGems) < 3.0.1.1, fixed in 3.0.1.1 . Check your lockfile, including transitive dependencies.

## What it is

A buffer-overread issue was discovered in StringIO 3.0.1, as distributed in Ruby 3.0.x through 3.0.6 and 3.1.x through 3.1.4. The ungetbyte and ungetc methods on a StringIO can read past the end of a string, and a subsequent call to StringIO.gets may return the memory value. 3.0.3 is the main fixed version; however, for Ruby 3.0 users, a fixed version is stringio 3.0.1.1, and for Ruby 3.1 users, a fixed version is stringio 3.0.1.2.

## Affected packages

- RubyGems `stringio` < 3.0.1.1 → fixed: 3.0.1.1

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 2.36% probability of exploitation activity in the next 30 days; percentile 84.

## Sources

- [GitHub Advisory GHSA-v5h6-c2hv-hv3r](https://github.com/advisories/GHSA-v5h6-c2hv-hv3r)
- [CVE.org record CVE-2024-27280](https://www.cve.org/CVERecord?id=CVE-2024-27280)
- [NVD entry CVE-2024-27280](https://nvd.nist.gov/vuln/detail/CVE-2024-27280)
- [hackerone.com](https://hackerone.com/reports/1399856)
- [ruby-lang.org](https://www.ruby-lang.org/en/news/2024/03/21/buffer-overread-cve-2024-27280/)
- [security.netapp.com](https://security.netapp.com/advisory/ntap-20250502-0003/)
- [seclists.org](http://seclists.org/fulldisclosure/2025/Sep/55)
- [seclists.org](http://seclists.org/fulldisclosure/2025/Sep/54)
- [seclists.org](http://seclists.org/fulldisclosure/2025/Sep/53)
- [lists.debian.org](https://lists.debian.org/debian-lts-announce/2024/09/msg00000.html)
- [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/27LUWREIFTP3MQAW7QE4PJM4DPAQJWXF/)
- [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XYDHPHEZI7OQXTQKTDZHGZNPIJH7ZV5N/)
- [github.com](https://github.com/ruby/stringio/commit/0e596524097706263d10900ca180898e4a8f5233)
- [github.com](https://github.com/ruby/stringio/commit/c58c5f54f1eab99665ea6a161d29ff6a7490afc8)
- [github.com](https://github.com/rubysec/ruby-advisory-db/blob/master/gems/stringio/CVE-2024-27280.yml)

---
Source page: https://erroneo.us/security/cve/CVE-2024-27280/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt