CVE Vulnerabilities

CVE-2026-54522

Use After Free

Published: Jul 30, 2026 | Modified: Aug 05, 2026
CVSS 3.x
5.4
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM
root.io logo minimus.io logo echo.ai logo

MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Buffer#clear in ext/msgpack/buffer.c leaves rmem_last, rmem_end, and rmem_owner stale after _msgpack_buffer_shift_chunk returns an rmem page to the shared pool, allowing a subsequent Buffer#write and a second MessagePack::Buffer to alias the page and disclose or corrupt cross-buffer data. This issue is fixed in version 1.8.2.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

NameVendorStart VersionEnd Version
MessagepackMsgpack*1.8.2 (excluding)
Ruby-msgpackUbuntuupstream*

Potential Mitigations

References