CVE-2026-8829: Oalders Html::entities

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

HTML::Entities versions before 3.84 for Perl read freed heap memory in _decode_entities. The XS routine backing HTML::Entities::_decode_entities cached a pointer (repl) into the entity-value SV returned by hv_fetch on the entity2char hash. When the input SV was identical to a value SV in that hash, and that value contained its own key as an entity reference, a later call to grow_gap() reallocated the SV's PV buffer and freed the backing allocation that repl still pointed into. The subsequent copy loop read repl_len bytes from the freed allocation. The read may disclose adjacent heap contents into the destination SV.

Affected products

• Oalders Html::entities: before 3.84 (fixed in 3.84)

Published 2026-06-04. Last modified 2026-07-22.