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Fencer Vulns
high 7.5

CVE-2026-8829 json

HTML::Entities versions before 3.84 for Perl read freed heap memory in _decode_entities

published 2026-06-04 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-34194

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

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.

Patch / fix

  • OALDERS HTML::Entities 3.84
  • libhtml-parser-perl Debian 12 3.81-1+deb12u1
  • libhtml-parser-perl Debian 13 3.83-2~deb13u1
  • libhtml-parser-perl Debian 14 3.83-2

debian advisories DEBIAN-CVE-2026-8829

  • libhtml-parser-perl Ubuntu 22.04 LTS 3.76-1ubuntu0.1
  • libhtml-parser-perl Ubuntu 24.04 LTS 3.81-1ubuntu0.1
  • libhtml-parser-perl Ubuntu 26.04 LTS 3.83-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-8829

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • perl-HTML-Parser SLE Module for Basesystem 15 SP7 3.830.0-150000.3.6.1
  • perl-HTML-Parser SLES for SAP applications 16.0, SLES 16.0 3.830.0-160000.3.1
  • perl-HTML-Parser SLES LTSS Extended Security 12 SP5 3.71-3.3.1

suse advisories SUSE-SU-2026:2950-1SUSE-SU-2026:2948-1SUSE-SU-2026:22189-1

  • perl-HTML-Parser openSUSE Leap 16.0 3.830.0-160000.3.1
  • perl-HTML-Parser openSUSE Tumbleweed 3.850.0-1.1

opensuse advisories openSUSE-SU-2026:21126-1openSUSE-SU-2026:10957-1

  • perl-HTML-Parser Azure Linux 3.0 3.82-2

azure linux advisories AZL-89451

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • OALDERS HTML::Entities

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.