CVE-2026-9769 (GCVE-0-2026-9769)
Vulnerability from cvelistv5 – Published: 2026-08-23 13:34 – Updated: 2026-08-24 17:54
VLAI
EPSS
VEX
Title
justhtml before 1.10.0 Denial of Service via deeply nested HTML
Summary
justhtml through 1.9.1 (fixed in 1.10.0) is vulnerable to uncontrolled recursion leading to denial of service. During JustHTML() construction, TreeBuilder.finish() unconditionally calls _populate_selectedcontent(), which recursively traverses the DOM tree via _find_elements()/_find_element() without a depth bound. An attacker who can supply HTML for parsing can provide deeply nested elements (e.g., ~1000 nested <div> tags, roughly 11 KB) to exceed CPython's default recursion limit and trigger an unhandled RecursionError, which may abort parsing, fail requests, or terminate a worker/process depending on the host application's exception handling.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-24 17:53 UTC
CWE
- CWE-674 - Uncontrolled Recursion
Assigner
VulnCheck
CNA
References
2 references
| URL | Tags |
|---|---|
| https://github.com/EmilStenstrom/justhtml/securit… | vendor-advisory |
| https://www.vulncheck.com/advisories/justhtml-bef… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| EmilStenstrom | justhtml |
Affected:
0 , < 1.10.0
(semver)
Unaffected: 1.10.0 (semver) |
Date Public
2026-03-15 00:00
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