CVE-2026-8829 | HTML::Entities versions before 3.84 for Perl read freed heap memory in _decode_entities

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.

Published: 2026-06-03 Last update: 2026-06-17 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-8829 is rated Low Risk (37.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.30%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-8829

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.30% +0.29%
2 2026-06-04 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-8829

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-8829

GitHub Security Advisory for CVE-2026-8829

GHSA-9p7j-9995-m88w · Severity: high — HTML::Entities versions before 3.84 for Perl read freed heap memory in _decode_entities. The XS...

OS Trackers for CVE-2026-8829

vendor priority summary link
debian not yet assigned CVE-2026-8829 not yet assigned priority: Debian including 1 source packages (libhtml-parser-perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-8829
suse medium CVE-2026-8829 severity moderate: SUSE including 1 source package names (perl-HTML-Parser-3.850.0-1.1), 1 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 1. https://www.suse.com/security/cve/CVE-2026-8829/
ubuntu medium CVE-2026-8829 medium priority: Ubuntu including 1 source packages (libhtml-parser-perl), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 8, released 1. https://ubuntu.com/security/CVE-2026-8829

Affected software / configurations for CVE-2026-8829

Vendor Product Version Raw CPE
oalders html::entities < 3.84 cpe:2.3:a:oalders:html\:\:entities:*:*:*:*:*:perl:*:*

References for CVE-2026-8829

cvelogic Threat Intelligence