CVE-2026-27120
6.1 · MEDIUMOverview
CVE-2026-27120 is a medium-severity vulnerability affecting vapor leafkit. It was published on February 20, 2026 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from vapor. Update leafkit to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| vapor | leafkit | >= 0, < 1.14.1 | Affected |
Frequently Asked Questions
What is CVE-2026-27120?
CVE-2026-27120 is a medium-severity vulnerability affecting vapor leafkit. It was published on February 20, 2026 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
How severe is CVE-2026-27120?
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-27120?
Check the references section for vendor advisories and patches from vapor. Update leafkit to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-27120?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-27120 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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