CVE-2025-6498: HTACG tidy-html5 · Memory Leak
Affects HTACG tidy-html5Source CVE Database V5
Public exploit available · CVSS 4.8 Medium.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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:PExploitation evidence
Disclosed: evidence found.
CVE published 23 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubhtacg/tidy-html5pkg:github/htacg/tidy-html5Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Monitor memory usage closely on systems running tidy-html5 5.8.0, especially on servers processing large volumes of HTML content or running continuous integration pipelines.
- Restrict local access to trusted users only, minimizing the risk of local exploitation.
- Implement resource limits (e.g., cgroups on Linux) on processes invoking tidy-html5 to prevent excessive memory consumption from impacting other services.
- Where feasible, replace or isolate the use of tidy-html5 5.8.0 in critical environments until a patched version is available.
- Employ containerization or sandboxing techniques to limit the impact of potential memory leaks.
- Stay updated with HTACG project releases and apply patches promptly once available.
- Conduct regular code audits and testing on HTML processing workflows to detect abnormal resource usage early.
- Educate local users and administrators about the vulnerability to prevent inadvertent exploitation or misuse.
Description
A vulnerability classified as problematic has been found in HTACG tidy-html5 5.8.0. Affected is the function defaultAlloc of the file src/alloc.c. The manipulation leads to memory leak. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used.