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 >= 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.
{
"cna_assigner": "CPANSec",
"cwe_ids": [
"CWE-125"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57075.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.47"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"fixed": "44c90a109ec3215ee7ce747bd11209835e123d8b"
}
],
"source": "REFERENCES_COMMIT"
}
]
}