CVE-2026-54522

MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Bufferclear in ext/msgpack/buffer.c leaves rmemlast, rmemend, and rmemowner stale after msgpackbuffershiftchunk returns an rmem page to the shared pool, allowing a subsequent...

CVE-2026-54522

MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Bufferclear in ext/msgpack/buffer.c leaves rmemlast, rmemend, and rmemowner stale after msgpackbuffershiftchunk returns an rmem page to the shared pool, allowing a subsequent...

CVE-2026-54522

CVE-2026-54522 affects MessagePack for Ruby prior to 1.8.2. The vulnerability lies in MessagePack::Buffer#clear in ext/msgpack/buffer.c, which leaves rmem_last, rmem_end, and rmem_owner stale after _msgpack_buffer_shift_chunk returns an rmem page to the shared pool. A subsequent Buffer#write by a...

CVE-2026-54522 MessagePack::Buffer#clear Use-After-Free that Enables Cross-Buffer Disclosure

MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Bufferclear in ext/msgpack/buffer.c leaves rmemlast, rmemend, and rmemowner stale after msgpackbuffershiftchunk returns an rmem page to the shared pool, allowing a subsequent...