CVE-2026-54522
MessagePack::Buffer#clear Use-After-Free that Enables Cross-Buffer Disclosure
- State
- Published
- Severity
- 2.1 Low
- Published
- Jul 30, 2026
- Updated
- Jul 30, 2026
- Reserved
- Jun 15, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.1 Low | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-416 Use After Free
Affected Products
| Product | Versions |
|---|---|
msgpack-rubymsgpack |
|
References
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.