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.
References
| Link | Resource |
|---|---|
| https://github.com/vapor/leaf-kit/commit/8919e39476c3a4ba05c28b71546bb9195f87ef34 | Patch |
| https://github.com/vapor/leaf-kit/security/advisories/GHSA-4hfh-fch3-5q7p | Exploit Vendor Advisory |
Configurations
History
02 Mar 2026, 13:34
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Vapor
Vapor leafkit |
|
| CPE | cpe:2.3:a:vapor:leafkit:*:*:*:*:*:*:*:* | |
| References | () https://github.com/vapor/leaf-kit/commit/8919e39476c3a4ba05c28b71546bb9195f87ef34 - Patch | |
| References | () https://github.com/vapor/leaf-kit/security/advisories/GHSA-4hfh-fch3-5q7p - Exploit, Vendor Advisory | |
| Summary |
|
20 Feb 2026, 22:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-02-20 22:16
Updated : 2026-03-02 13:34
NVD link : CVE-2026-27120
Mitre link : CVE-2026-27120
CVE.ORG link : CVE-2026-27120
JSON object : View
Products Affected
vapor
- leafkit
