CVE-2026-27120

Q: How do I fix CVE-2026-27120?

Upgrade leafkit to 1.14.1 or later.

Q: Is CVE-2026-27120 being actively exploited?

Not that we know of. CVE-2026-27120 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.23% is the estimated probability that it will be exploited in the next 30 days. That is higher than 14% of all scored CVEs.

Q: How severe is CVE-2026-27120?

CVE-2026-27120 has a CVSS v3 base score of 6.1, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-27120 affect?

Published advisories record a fix for leafkit (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

MEDIUM

6.1

CVSS v3

NVD

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.

CWE-75 CWE-79Cross-Site Scripting (XSS)CWE-87

How to fix

Remediation Available

leafkitNVD

Affected:< 1.14.1Fixed in:1.14.1CVE-2026-27120derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

0.23%probability of exploitation in 30 days

14thpercentile

Low risk: more likely to be exploited than 14% of all known CVEs.

References

Patch1

github.com

Exploit1

github.com

Related Vulnerabilities

Other CWE-75 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2021-22911	Critical	9.8	95%	-	-
CVE-2024-0801	High	7.5	42%	-	-
CVE-2021-39174	High	8.8	3.9%	-	Fix
CVE-2023-40743	Critical	9.8	2.6%	-	Fix
CVE-2026-29042	Critical	9.8	2.3%	-	Fix
CVE-2021-22910	Critical	9.8	2.3%	-	Fix

Common questions

How do I fix CVE-2026-27120?

Upgrade leafkit to 1.14.1 or later.

Is CVE-2026-27120 being actively exploited?

Not that we know of. CVE-2026-27120 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.23% is the estimated probability that it will be exploited in the next 30 days. That is higher than 14% of all scored CVEs.

How severe is CVE-2026-27120?

CVE-2026-27120 has a CVSS v3 base score of 6.1, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-27120 affect?

Published advisories record a fix for leafkit (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-27120

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-02.