CVE-2026-27120

Summary

Leafkit is a templating language with Swift-inspired syntax. Prior to 1.4.1, htmlEscaped in leaf-kit will only escape html special characters if the extended grapheme clusters match, which allows bypassing escaping by using an extended grapheme cluster containing both the special html character and some additional characters. In the case of html attributes, this can lead to XSS if there is a leaf variable in the attribute that is user controlled. This vulnerability is fixed in 1.4.1.

Affected Software

VendorProductVersion RangeStatus
vaporleaf-kit< 1.4.1affected

Weaknesses

  • CWE-75: CWE-75: Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
  • CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-87: CWE-87: Improper Neutralization of Alternate XSS Syntax

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

References