جزئیات آسیب‌پذیری

Inefficient Regular Expression Complexity vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to exhaust server CPU via a long CSS declaration in sanitized HTML. The declaration regex in HtmlSanitizeEx.Scrubber.CSS.scrub/1 matches the property name with an unbounded greedy [-\w]+ followed by a mandatory :, so a long run of word characters not followed by a colon makes the engine give back one character at a time and retry the colon at every start offset. The work is quadratic in the length of the run, and no length cap is applied to the CSS handed to the scrubber. An 80 KB <style> body costs roughly 2.4 seconds of scheduler time, so a few concurrent requests saturate the BEAM scheduler pool and make the application unresponsive. The impact is CPU exhaustion only. Nothing is read, modified or disclosed. This issue affects html_sanitize_ex: from 0.3.1 before 1.4.5 and from 1.5.0-rc.0 before 1.5.3.

• https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-4cx2-987x-rr2x vendor-advisoryrelated
• https://cna.erlef.org/cves/CVE-2026-68749.html related
• https://osv.dev/vulnerability/EEF-CVE-2026-68749 related
• https://github.com/rrrene/html_sanitize_ex/commit/4f4bd9eb254881462c0461fbab74b29188c2c133 patch
• https://github.com/rrrene/html_sanitize_ex/commit/b673df33ddf982c8bd0a8bd6348aa247080b3b14 patch