P4Verified

CVE-2026-5388: justhtml 0 to before 1.15.0

CVE-2026-5388. CVSS 3.1 base score 9.8 (CRITICAL, Vendor/CNA). EPSS 0.00587 (percentile 0.46518), scored 11-Oct-2026.

Affected technology

justhtml · 0 to before 1.15.0
EmilStenstrom

Description’s affected range: before 1.15.0

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 4.0): Network (remote) · No privileges required · No user interaction required

What an attacker can do

An attacker can bypass sanitization to inject active HTML and JavaScript — for example via encoded javascript: URLs, backslash-based relative URLs resolved as remote hosts, markup-breaking programmatic element/attribute names or HTML comments, raw reintroduction through Markdown passthrough, or preserved. Vendor/CNA’s CVSS 4.0 assessment (base score 9.3/10) rates confidentiality, integrity and availability impact as high.

Published 12-Oct-2026 16:54 UTC

CWE: CWE-20
CCR priority: 39.3 /100 (P4)
CVSS 3.1: 9.8 /10 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H · Vendor/CNA
EPSS: 0.00587 · percentile 0.46518 · 2026-10-11
KEV: no

Provenance

NVD CVE API 2.0 · Source record · observed 2026-10-12 16:54:24.294989+00:00 UTC

Stable permalink: https://cybercodered.org/item/cve-cve-2026-5388.html