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CVE-2025-6497— HTACG tidy-html5 parser.c prvTidyParseNamespace assertion

Quick assessment

Affected

HTACG tidy-html5

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

HTACG HTML Tidy是HTML Tidy Advocacy Community Group开源的一个 HTML 工具。 HTACG HTML Tidy 5.8.0版本存在安全漏洞，该漏洞源于src/parser.c文件中prvTidyParseNamespace函数存在可达断言问题。

CVSS 3.3 · Low EPSS 0.17% · P6 Updated Jul 05, 2025

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

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I. Basic Information for CVE-2025-6497

Vulnerability Information

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Vulnerability Title

HTACG tidy-html5 parser.c prvTidyParseNamespace assertion

Source: CVE Program / CVE List V5

Vulnerability Description

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.

Source: CVE Program / CVE List V5

CVSS Information

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

Source: CVE Program / CVE List V5

Vulnerability Type

可达断言

Source: CVE Program / CVE List V5

Vulnerability Title

HTACG HTML Tidy 安全漏洞

Source: CNNVD (China National Vulnerability Database)

Vulnerability Description

Source: CNNVD (China National Vulnerability Database)

CVSS Information

N/A

Source: CNNVD (China National Vulnerability Database)

Vulnerability Type

N/A

Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
HTACG	tidy-html5	5.8.0	-

II. Public POCs for CVE-2025-6497

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2025-6497

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Proof of Concept for CVE-2025-6497 (1)

🔗 [BUG] Assertion `parent` failed in `Node *prvTidyParseNamespace(TidyDocImpl *, Node *, GetTokenMode)` at `src/parser.c:4120` · Issue #1142 · htacg/tidy-html5 Read full article issue-tracking

Other References for CVE-2025-6497 (1)

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

https://www.cve.org/CVERecord?id=CVE-2025-6497

Same Patch Batch · HTACG · 2025-06-23 · 3 CVEs total

CVE-2025-6498	3.3 LOW	HTACG tidy-html5 alloc.c defaultAlloc memory leak
CVE-2025-6496	3.3 LOW	HTACG tidy-html5 parser.c InsertNodeAsParent null pointer dereference

IV. Related Vulnerabilities

Same product: tidy-html5

Same vendor: HTACG

Same weakness: CWE-617