CVE-2026-8829

HIGHCVSS 7.5/10EPSS 0.30%

Last modified

CVE-2026-8829 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.30% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability
0.30%

22.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
OaldersHtml\< 3.84Entities

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-8829?
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.
How severe is CVE-2026-8829?
CVE-2026-8829 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.
How do I fix CVE-2026-8829?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-8829?

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Source: NVD / NIST