CVE-2026-50290 (GCVE-0-2026-50290)

Vulnerability from cvelistv5 – Published: 2026-08-21 19:55 – Updated: 2026-08-21 20:07
VLAI
Title
@asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString
Summary
SpecifyJS is a declarative TypeScript user interface framework. Prior to version 0.2.136, CSS value sanitization stripped `expression(` and `url(javascript:` using simple regex, but could be bypassed with CSS unicode escapes (`\65xpression(`), null bytes, or CSS comments (`exp/**/ression(`). These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers. Starting in version 0.2.136, CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for `behavior:`, `-moz-binding`, and `-o-link` patterns.
Severity
5.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-21 20:07 UTC
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version
asymmetric-effort specifyjs Affected: < 0.2.136
Create a notification for this product.
Show details on NVD website
To clipboard 

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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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