CVE-2026-28499 | THREATINT

Description

LeafKit is a templating language with Swift-inspired syntax. Prior to version 1.14.2, HTML escaping doesn't work correctly when a template prints a collection (Array / Dictionary) via `#(value)`. This can result in XSS, allowing potentially untrusted input to be rendered unescaped. Version 1.14.2 fixes the issue.

PUBLISHED Reserved 2026-02-27 | Published 2026-03-18 | Updated 2026-03-18 | Assigner GitHub_M

MEDIUM: 6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N

Problem types

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

CWE-116: Improper Encoding or Escaping of Output

Product status

< 1.14.2

affected

References

github.com/...af-kit/security/advisories/GHSA-6jj5-j4j8-8473 exploit

github.com/...af-kit/security/advisories/GHSA-6jj5-j4j8-8473

github.com/...ommit/6044b844caa858a0c5f2505ac166f5a057c990dc

github.com/vapor/leaf-kit/releases/tag/1.14.2

cve.org (CVE-2026-28499)

nvd.nist.gov (CVE-2026-28499)

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