CVE-2025-6497 HTACG tidy-html5 parser.c prvTidyParseNamespace assertion
A local attacker can trigger a reachable assertion in the tidy-html5 parser, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-6497?
CVE-2025-6497 is a medium-severity denial of service vulnerability in HTACG tidy-html5, published on 23 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-617
Which versions are affected by CVE-2025-6497?
How do I fix CVE-2025-6497?
No fix has been published for CVE-2025-6497 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-6497 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6497 exists.
Sources
Also known as AZL-64317, AZL-64323, DEBIAN-CVE-2025-6497, GHSA-2843-f6r8-wh6v, UBUNTU-CVE-2025-6497.