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

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SUSE 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...

AZL-94449 CVE-2026-54522 affecting package rubygem-msgpack for versions less than 1.8.4-1

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

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...

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

Summary MessagePack::Bufferclear shifts out every chunk and returns its 4 KiB rmem page to the shared pool, but does not reset the buffer's rmem cursor rmemlast, rmemend, rmemowner. The next write sees "unused rmem space" left over from the freed page and hands back a slice of memory that has...

GHSA-4MRV-5P47-P938 MessagePack::Buffer#clear Use-After-Free that Enables Cross-Buffer Disclosure

Summary MessagePack::Bufferclear shifts out every chunk and returns its 4 KiB rmem page to the shared pool, but does not reset the buffer's rmem cursor rmemlast, rmemend, rmemowner. The next write sees "unused rmem space" left over from the freed page and hands back a slice of memory that has...

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...

EUVD-2026-51235

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::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...

CVE-2026-54522

CVE-2026-54522 affects MessagePack for Ruby prior to 1.8.2, where MessagePack::Buffer#clear can leave internal rmem pointers stale after a chunk return, enabling a subsequent Buffer#write to alias the freed page and potentially disclose or corrupt cross-buffer data. Root cause: stale rmem_last/rm...

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::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...

PT-2026-66639

Summary MessagePack::Bufferclear shifts out every chunk and returns its 4 KiB rmem page to the shared pool, but does not reset the buffer's rmem cursor rmem last, rmem end, rmem owner. The next write sees "unused rmem space" left over from the freed page and hands back a slice of memory that has...

PT-2026-66528

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 rmem last, rmem end, and rmem owner stale after msgpack buffer shift chunk returns an rmem page to the shared pool, allowing a subseque...