{"id":"DEBIAN-CVE-2026-54522","details":"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.","modified":"2026-09-14T17:03:20.168502382Z","published":"2026-07-30T17:16:33.030Z","upstream":["CVE-2026-54522"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-54522"}],"affected":[{"package":{"name":"ruby-msgpack","ecosystem":"Debian:12","purl":"pkg:deb/debian/ruby-msgpack?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.2-2","1.7.2-1","1.7.2-1.1","1.8.0-1","1.8.3-1","1.8.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54522.json"}},{"package":{"name":"ruby-msgpack","ecosystem":"Debian:13","purl":"pkg:deb/debian/ruby-msgpack?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.2-1.1","1.8.0-1","1.8.3-1","1.8.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54522.json"}},{"package":{"name":"ruby-msgpack","ecosystem":"Debian:14","purl":"pkg:deb/debian/ruby-msgpack?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.3-1"}]}],"versions":["1.7.2-1.1","1.8.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54522.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"}]}