CVE-2026-54522
Published:July 30, 2026
Updated:August 03, 2026
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.
Affected Packages
https://github.com/msgpack/msgpack-ruby.git (GITHUB):
Affected version(s) >=v0.5.0 <v1.8.2Fix Suggestion:
Update to version v1.8.2msgpack (RUBY):
Affected version(s) >=0.0.1 <1.8.2Fix Suggestion:
Update to version 1.8.2Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
2.1
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Use After Free
EPSS
Base Score:
0.12