SEPTEMBER 19, 2026
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Case File

CVE-2026-4671

HIGH · CVSS 7.5 EPSS 0.37% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-23 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

JustHTML versions prior to 1.18.0 are vulnerable to multiple denial-of-service issues stemming from improper handling of CSS selectors and linkification, which can lead to excessive CPU or memory consumption when processing attacker-controlled input. Applications that utilize functions like query(), matches(), or selector-based transformations with untrusted documents are particularly at risk. Organizations using JustHTML should prioritize updating to the latest version to mitigate these availability concerns.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-4671
Severity
HIGH
CVSS
7.5
EPSS
0.37%

Original NVD Description

justhtml before 1.18.0 contains multiple low-severity denial-of-service issues in CSS selector handling and linkification. Applications that evaluate attacker-controlled selector strings (via query(), matches(), or selector-based transforms), run selector matching over very large untrusted documents, construct DOM trees from untrusted structure, or enable linkification over attacker-controlled text may consume disproportionate CPU or memory. Triggers include oversized selectors, large selector lists, oversized compound selectors, long combinator chains, deeply nested functional pseudo-classes, repeated token/positional matching, cyclic DOM graphs causing non-terminating traversal, and punctuation-heavy or trailing-bracket linkification input. These are availability-only concerns and do not by themselves allow script execution, data disclosure, or sanitizer bypass. Default JustHTML(sanitize=True) usage is not expected to be exposed, since selectors are normally supplied by application code.