TI-2025-05898 Aliases CVE-2025-6497 GHSA-2843-f6r8-wh6v

HTACG tidy-html5 parser.c prvTidyParseNamespace assertion

MEDIUM 55CWE-617Published 2025-06-23 · Updated 2025-06-23

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-617.

Summary

A vulnerability was found in HTACG tidy-html5 5.8.0. It has been rated as problematic. This issue affects the function prvTidyParseNamespace of the file src/parser.c. The manipulation leads to reachable assertion. Attacking locally is a requirement. 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 0.00167 5th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by 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

Vendor	Product	Affected versions	Fixed in	Status	Source
HTACG	tidy-html5	5.8.0	—	No fix listed	CNA

tidy-html5 VendorHTACG Affected 5.8.0 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2025-6497
2026-10-03 Alias added: GHSA-2843-f6r8-wh6v

References

Exploit 1

https://github.com/user-attachments/files/19825297/tidy-html5_crash_2.txt

Other 1

https://github.com/htacg/tidy-html5/issues/1142

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-2025-05899 HTACG tidy-html5 alloc.c defaultAlloc memory leak CVSS 4.0MEDIUM 4.8
TI-2025-05897 HTACG tidy-html5 parser.c InsertNodeAsParent null pointer dereference CVSS 4.0MEDIUM 4.8
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

See all 7 →

Sources

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