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CRITICAL severity

CVE-2024-27280 stringio

CRITICAL

CVE-2024-27280 is a critical-severity (CVSS 9.8) CWE-120 vulnerability in stringio. A fix is available for stringio — see the affected versions and patch details below.

StringIO buffer overread vulnerability

Also known asGHSA-v5h6-c2hv-hv3r
Published
May 14, 2024
Updated
Apr 16, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-27280.

EPSS Exploitation Probability

via FIRST.org ↗
2.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs83th percentile — riskier than 83% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2024-27280 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
💎stringio

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

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

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
💎RubyGemsstringioall versions3.0.1.1bundle update stringio --conservative

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for stringio, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update stringio to 3.0.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27280 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-27280 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2024-27280. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
ProductFixed inAdvisory
Red Hat Enterprise Linux 8ruby:3.0-8100020240522072634.489197e6RHSA-2024:3500
Red Hat Enterprise Linux 8ruby:3.1-8100020240510101534.489197e6RHSA-2024:3546
Red Hat Enterprise Linux 8ruby:3.3-8100020240522151542.489197e6RHSA-2024:3670
Red Hat Enterprise Linux 8ruby:2.5-8100020240627152904.489197e6RHSA-2024:4499
Red Hat Enterprise Linux 9ruby:3.1-9040020240503183840.9RHSA-2024:3668
Red Hat Enterprise Linux 9ruby:3.3-9040020240522171337.9RHSA-2024:3671
Red Hat Enterprise Linux 9ruby-0:3.0.7-162.el9_4RHSA-2024:3838

Frequently Asked Questions

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.
O3 Security · Impact-Aware SCA

Is CVE-2024-27280 in your dependencies?

O3 Security finds CVE-2024-27280 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2024-27280: stringio (Critical 9.8) | O3 Security