CVE-2026-30838
CommonMark has DisallowedRawHtml extension bypass via whitespace in HTML tag names
描述
league/commonmark is a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting a newline, tab, or other ASCII whitespace character between a disallowed HTML tag name and the closing >. For example, <script\n> would pass through unfiltered and be rendered as a valid HTML tag by browsers. This is a cross-site scripting (XSS) vector for any application that relies on this extension to sanitize untrusted user input. All applications using the DisallowedRawHtml extension to process untrusted markdown are affected. Applications that use a dedicated HTML sanitizer (such as HTML Purifier) on the rendered output are not affected. This issue has been patched in version 2.8.1.
如何修補 CVE-2026-30838
要修補 CVE-2026-30838,請將受影響套件升級到下列已修補版本。
- —未列出修補版本
- —升級至 2.8.1 或更新版本
CVE-2026-30838 正在被利用嗎?
低 — EPSS 為 0.2%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0
- >= 2.0.0, < 2.8.1
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |