- 4.8MediumCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By VulDB
- 1 day later
· 1 day later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium4.8 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P |
| VulDBCNA (assigner) | 3.1 | Low3.3 | 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 |
| VulDBCNA (assigner) | 3.0 | Low3.3 | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 2.0 | Low1.7 | AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR |
| NVDNVD · Deferred | 4.0 | Low1.9 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.8.
Affected products
- affected 5.8.0
References
References5
- VDB-313613 | HTACG tidy-html5 parser.c prvTidyParseNamespace assertion (opens in a new tab)vdb-entrytechnical-description
- VDB-313613 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- Submit #601008 | htacg tidy-html5 tidy-html5 5.8.0 (commit d08ddc2) Reachable Assertion (opens in a new tab)third-party-advisory
- https://github.com/htacg/tidy-html5/issues/1142 (opens in a new tab)issue-tracking
- https://github.com/user-attachments/files/19825297/tidy-html5_crash_2.txt (opens in a new tab)exploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-18860 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-6497)Record last updated .