CVE-2026-41591

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a ,...

CVE-2026-41591

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker...

CVE-2026-41591

The CVE affects Marko and @marko/runtime-tags, where dynamic text inside , ), enabling cross-site scripting (XSS) if untrusted input is interpolated inside these blocks. Affected versions are Marko <= 5.38.35 and @marko/runtime-tags <= 6.0.163; the issue is patched in Marko 5.38.36 and @mar...

@marko/translator-interop-class-tags (>=0.1.1, <=0.2.24), @marko/translator-tags (>=0.1.1, <=0.4.8) potentially affected by CVE-2026-41591 via @marko/runtime-tags (>=0.1.25, <=0.3.86)

@marko/runtime-tags NPM version =0.1.25, =0.1.1, =0.1.1, =0.4.8 Source cves: CVE-2026-41591 Source advisory: MEND:CVE-2026-41591...

CVE-2026-41591 Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker...

CVE-2026-41591

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a ,...

CVE-2026-41591 Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker...

@27works/posto (2.0.2), @awly/lasso (3.2.4) +183 more potentially affected by CVE-2026-41591 via marko (>=1.6.11, <=5.21.7)

marko NPM version =1.6.11, =1.15.0, =1.0.0-alpha.1, =1.0.0-beta.4, =1.0.0-beta.4, =0.4.15, =1.26.0, =0.4.16, =0.1.0, =0.2.0, =0.0.1, =1.0.0, =1.0.1, =1.1.1 and more Source cves: CVE-2026-41591 Source advisory: MEND:CVE-2026-41591...

CVE-2026-41591 Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker...

Marko cross-site scripting vulnerabilities

Marko is an open-source declarative HTML language used for building dynamic user interfaces. Versions of Marko prior to 5.38.36 contained a cross-site scripting vulnerability. This vulnerability occurred when dynamic text was inserted into script or style tags without preventing the escape of...

CVE-2026-41591: Improper Neutralization of Input During Web Page Generation

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a , , etc. and inject arbitrary HTML/JavaScript, resulting in cross-site scripting. This issue has been patched in mar...

@marko/compiler (5.0.0-next.0), @marko/translator-default (5.0.0-next.0) +4 more potentially affected by CVE-2026-41591 via marko (>=5.0.0-next.0, <=5.21.7)

marko NPM version =5.0.0-next.0, =2.9.2, =1.15.0, =1.1.4, =1.2.1 Source cves: CVE-2026-41591 Source advisory: GHSA-X9FJ-57FH-C8WQ...

Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping

Summary When dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker able to place input inside a or block could break out of the tag with , , etc. and inject arbitrary HTML/JavaScript, resulting in...

Cross-site Scripting (XSS)

Overview @marko/runtime-tags is an Optimized runtime for Marko templates. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the handling of interpolated values within or tags due to improper case-insensitive detection of closing tags. An attacker can execute arbitrar...

@marko/compiler (5.0.0-next.0), @marko/translator-default (5.0.0-next.0) +4 more potentially affected by CVE-2026-41591 via marko (>=5.0.0-next.0, <=5.21.7)

marko NPM version =5.0.0-next.0, =2.9.2, =1.15.0, =1.1.4, =1.2.1 Source cves: CVE-2026-41591 Source advisory: SNYK:JS-MARKO-16421453...

@marko/compiler (5.0.0-next.0), @marko/translator-default (5.0.0-next.0) +4 more potentially affected by CVE-2026-41591 via marko (>=5.0.0-next.0, <=5.21.7)

marko NPM version =5.0.0-next.0, =2.9.2, =1.15.0, =1.1.4, =1.2.1 Source cves: CVE-2026-41591 Source advisory: OSV:GHSA-X9FJ-57FH-C8WQ...

Cross-site Scripting (XSS)

Overview marko is an UI Components + streaming, async, high performance, HTML templating for Node.js and the browser. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the handling of interpolated values within or tags due to improper case-insensitive detection of...

GHSA-X9FJ-57FH-C8WQ Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping

Summary When dynamic text is interpolated into a or tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker able to place input inside a or block could break out of the tag with , , etc. and inject arbitrary HTML/JavaScript, resulting in...

CVE-2026-41591

creationtimestamp| type| source ---|---|--- 2026-04-18 00:29:59+00:00| published-proof-of-concept| https://github.com/marko-js/marko/security/advisories/GHSA-x9fj-57fh-c8wq...

CVE-2025-62146

Improper Neutralization of Input During Web Page Generation 'Cross-site Scripting' vulnerability in Maksym Marko MX Time Zone Clocks mx-time-zone-clocks allows Stored XSS.This issue affects MX Time Zone Clocks: from n/a through = 5.1.1...