CVE-2026-27120 (GCVE-0-2026-27120)

Vulnerability from cvelistv5 – Published: 2026-02-20 21:27 – Updated: 2026-02-24 18:41
VLAI
Title
Leaf-kit html escaping does not work on characters that are part of extended grapheme cluster
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.
Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-02-24 18:40 UTC
CWE
  • CWE-75 - Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-87 - Improper Neutralization of Alternate XSS Syntax
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7994 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
vapor leaf-kit Affected: < 1.4.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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