CVE-2026-27120
Last modified
CVE-2026-27120 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 0.23% chance of exploitation in the next 30 days.
Description
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Vapor | Leafkit | < 1.14.1 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-27120?
How severe is CVE-2026-27120?
How do I fix CVE-2026-27120?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-27115ADB Explorer is a fluent UI for ADB on Windows. Versions 0.9…7.1
- CVE-2026-27116Vikunja is an open-source self-hosted task management platfo…6.1
- CVE-2026-27117bit7z is a cross-platform C++ static library that allows the…7.5
- CVE-2026-27118SvelteKit is a framework for rapidly developing robust, perf…5.3
- CVE-2026-27119svelte performance oriented web framework. From 5.39.3, <=5.…5.4
- CVE-2026-2712The WP-Optimize plugin for WordPress is vulnerable to unauth…5.4
- CVE-2026-27121svelte performance oriented web framework. Versions of svelt…5.4
- CVE-2026-27122svelte performance oriented web framework. Prior to 5.51.5, …5.4
- CVE-2026-27123Rejected reason: Reason: This candidate was issued in error.
- CVE-2026-27124FastMCP is the standard framework for building MCP applicati…6.1
- CVE-2026-27125svelte performance oriented web framework. Prior to 5.51.5, …6.8
- CVE-2026-27126Craft is a content management system (CMS). In versions 4.5.…4.8
Are you affected by CVE-2026-27120?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST