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TI-2025-05899 Aliases CVE-2025-6498GHSA-449v-6j3r-mxhj

HTACG tidy-html5 alloc.c defaultAlloc memory leak

Priority MEDIUM 55CWE-401Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-401.

Summary

A vulnerability classified as problematic has been found in HTACG tidy-html5 5.8.0. Affected is the function defaultAlloc of the file src/alloc.c. The manipulation leads to memory leak. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00239 15th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD and the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
HTACGtidy-html55.8.0—No fix listedCNA
  • tidy-html5 VendorHTACG Affected 5.8.0 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:htacg:tidy:5.8.0:*:*:*:*:*:*:*5.8.0VulnerableHTACG
  • cpe:2.3:a:htacg:tidy:5.8.0:*:*:*:*:*:*:* Versions 5.8.0 Vulnerable ·HTACG

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-6498
  2. 2026-10-03 Alias added: GHSA-449v-6j3r-mxhj

References

Exploit 2

  • TI-2021-12836 An issue in HTACG HTML Tidy v5.7.28 allows attacker to execute arbitrary code via the -g… CVSS 3.1CRITICAL 9.8
  • TI-2015-04650 Heap-based buffer overflow in the ParseValue function in lexer.c in tidy before 4.9.31… CVSS 2.0MEDIUM 6.8
  • TI-2017-12775 In Tidy 5.7.0, the prvTidyTidyMetaCharset function in clean.c allows attackers to cause a… CVSS 3.1HIGH 7.5
  • TI-2017-09969 In Tidy 5.5.31, the IsURLCodePoint function in attrs.c allows attackers to cause a denial… CVSS 3.0HIGH 7.5
  • TI-2015-04651 The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause… CVSS 2.0MEDIUM 4.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences