CVE-2026-5388

Katalog CVE

CVSS 9.8 · Critical EPSS 0,59%

Kerentanan Improper Input Validation. Skor CVSS 3.1 9.8 (Critical) menurut vulncheck.com.

Deskripsi (NVD)

justhtml before 1.15.0 contains multiple security issues in URL sanitization helpers (clean_url_value/clean_url_in_js_string), HTML serialization, Markdown passthrough (html_passthrough=True), and several custom sanitization-policy edge cases. Depending on configuration, 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 </textarea> reintroduction through Markdown passthrough, or preserved <style>/<meta http-equiv=refresh>/<base href> tags in custom policies. Most custom-policy issues do not affect the default sanitize=True configuration; they primarily affect helper APIs, programmatic DOM construction, html_passthrough=True, and custom policies/transform pipelines.

Rincian

Terbit di NVD

23 Agustus 2026

Terakhir diubah

12 Oktober 2026

Status NVD

Deferred

CVSS 3.1

9.8 (Critical), sumber vulncheck.com
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-20: Improper Input Validation

EPSS (30 hari)

0,59% peluang dieksploitasi; lebih tinggi dari 46,6% CVE lain

Produk dan versi terdampak

NVD belum mencantumkan data produk (CPE) untuk CVE ini. Produk yang terdampak biasanya disebut di deskripsi dan di advisory vendor pada daftar referensi.

Referensi dan perbaikan

• https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-c9vm-hv86-f23r
• https://www.vulncheck.com/advisories/justhtml-before-multiple-security-issues