Cpanel::JSON::XS versions before 4.80 for Perl leak the decoded arguments of a tagged value when its THAW method dies in decode_tag.
With allow_tags, a tagged value's class name and argument array are decoded and passed to the class's THAW method. Both are released only after THAW returns, so a THAW that dies leaves the whole decoded argument structure allocated.
Each rejected document leaks data of a size the sender chooses, so a process that catches the error and keeps running exhausts its memory.
{
"cna_assigner": "CPANSec",
"cwe_ids": [
"CWE-401"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110685.json"
}