{"id":"UBUNTU-CVE-2026-57075","details":"YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via a signed-char lookup-table index in syck_base64dec. The base64 decoder in the bundled libsyck indexes the 256-entry static table b64_xtable with a signed char, so any !!binary byte \u003e= 0x80 sign-extends to a negative index and reads before the table. The decoder receives the raw bytes of any !!binary node, a standard YAML type not gated by $LoadBlessed or $LoadCode, so it is reached on the default Load path. Any caller that runs Load or LoadFile on an untrusted document containing a !!binary scalar with a high-bit byte triggers the read, and the value read can surface in the decoded result.","modified":"2026-07-29T07:59:16Z","published":"2026-07-16T22:17:00Z","upstream":["CVE-2026-57075"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-57075"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-57075"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2026/07/17/2"},{"type":"REPORT","url":"https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch"},{"type":"REPORT","url":"https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes"},{"type":"REPORT","url":"http://www.openwall.com/lists/oss-security/2026/07/17/2"}],"affected":[{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.27-2build2","1.29-1","1.29-1build1","1.29-1ubuntu0.16.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.29-1ubuntu0.16.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}},{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.29-1build3","1.29-1ubuntu0.18.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.29-1ubuntu0.18.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}},{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.31-1","1.31-1build1","1.31-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.31-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}},{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.34-1build1","1.34-1build2","1.34-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.34-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}},{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.34-2","1.34-2build1","1.34-2build2","1.34-2build3","1.34-2ubuntu0.24.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.34-2ubuntu0.24.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}},{"package":{"name":"libyaml-syck-perl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libyaml-syck-perl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.34-3","1.34-4","1.36-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libyaml-syck-perl","binary_version":"1.36-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-57075.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}