Heap-use-after-free vulnerability in mruby

mruby Updated 02 Oct 2025

Summary

14/03/2023

Disclosed on

HIGH

Severity

Yes i

Fix available

High

Severity

Not published

CVSS Score

OSV-2023-176: Heap-use-after-free in mrb_gc_mark. Affects mruby versions >= 0e51da81bb7981a5005ca22c95384056bcb87671, < 8d1192f8a28034b1931a41e8c55cd86715101d0c. Fixed in 8d1192f8a28034b1931a41e8c55cd86715101d0c. How to fix ↓

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Background

mruby is an open-source lightweight implementation of the Ruby programming language. It is designed to be embedded in other applications and provides a minimalistic and efficient runtime environment. The vulnerability in question is a heap-use-after-free issue that affects the garbage collector (GC) functionality of mruby.

Vulnerability Detail

The vulnerability arises due to a heap-use-after-free condition in the mrb_gc_mark function of mruby. This can lead to a crash when attempting to read from a freed memory location. The issue was discovered and reported by OSS-Fuzz, and more details can be found in their bug report (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=56991). The severity of this vulnerability is considered high.

How To Fix

Minimum fixed version

8d1192f8a28034b1931a41e8c55cd86715101d0c

This is the first release that contains the fix.

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Workaround

There is no specific workaround mentioned for this vulnerability.

Conclusion

In conclusion, the mruby package is affected by a heap-use-after-free vulnerability in the mrb_gc_mark function. It is recommended to update to a version of mruby that includes the fix for this vulnerability. For further support and assistance with vulnerability remediation, please contact DevNack.com.

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