Vulnerability · Published Jun 23, 2025 · Assigned by VulDB
CVE-2025-6496HTACG tidy-html5 parser.c InsertNodeAsParent null pointer dereference
Low 3.3
In plain English
A low-severity null pointer dereference in tidy-html5 from HTACG. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).
Severity (CVSS 3.1)3.3Low
Exploit odds (30 days)0.2%top 94.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
A vulnerability was found in HTACG tidy-html5 5.8.0. It has been declared as problematic. This vulnerability affects the function InsertNodeAsParent of the file src/parser.c. The manipulation leads to null pointer dereference. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | tidy-html5 | no fix listed | DEBIAN-CVE-2025-6496 |
| Debian:13 | tidy-html5 | no fix listed | DEBIAN-CVE-2025-6496 |
| Debian:14 | tidy-html5 | no fix listed | DEBIAN-CVE-2025-6496 |
| Ubuntu:22.04:LTS | tidy-html5 | no fix listed | UBUNTU-CVE-2025-6496 |
| Ubuntu:24.04:LTS | tidy-html5 | no fix listed | UBUNTU-CVE-2025-6496 |
| Ubuntu:25.10 | tidy-html5 | no fix listed | UBUNTU-CVE-2025-6496 |
| Ubuntu:26.04:LTS | tidy-html5 | no fix listed | UBUNTU-CVE-2025-6496 |
| Ubuntu:26.10 | tidy-html5 | no fix listed | UBUNTU-CVE-2025-6496 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| HTACG | tidy-html5 | 5.8.0 |
Weakness: CWE-476, CWE-404 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
References
- VDB-313612 | HTACG tidy-html5 parser.c InsertNodeAsParent null pointer dereference vdb-entry, technical-description
- VDB-313612 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- Submit #601007 | htacg tidy-html5 tidy-html5 5.8.0 (commit d08ddc2) NULL Pointer Dereference third-party-advisory
- https://github.com/htacg/tidy-html5/issues/1141 issue-tracking
- https://github.com/user-attachments/files/19652942/tidy-html5_crash.txt exploit