CVE-2026-65912

Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It is due to an incomplete fix for a previous issue. This vulnerability can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).

Recommendation

Upgrade to version 3.0.8, 4.5.3 or later.

DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. Attackers can supply a predicate that accepts specific attribute and tag combinations to bypass URI-safe validation, allowing unsafe protocols like javascript: to survive sanitization and execute as DOM-based XSS when the link is activated.

DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. Attackers can supply a predicate that accepts specific attribute and tag combinations to bypass URI-safe validation, allowing unsafe protocols like javascript: to survive sanitization and execute as DOM-based XSS when the link is activated.

DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. Attackers can supply a predicate that accepts specific attribute and tag combinations to bypass URI-safe validation, allowing unsafe protocols like javascript: to survive sanitization and execute as DOM-based XSS when the link is activated.

Versions of handlebars prior to 3.0.8 or 4.5.2 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).

The following template can be used to demonstrate the vulnerability:

	{{#with split as |a|}}
		{{pop (push "alert('Vulnerable Handlebars JS');")}}
		{{#with (concat (lookup join (slice 0 1)))}}
			{{#each (slice 2 3)}}
				{{#with (apply 0 a)}}
					{{.}}
				{{/with}}
			{{/each}}
		{{/with}}
	{{/with}}
{{/with}}```


## Recommendation

Upgrade to version 3.0.8, 4.5.2 or later.

Summary

DOMPurify allows ADD_ATTR to be provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. When the predicate returns true, _isValidAttribute short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as <a href="javascript:alert(document.domain)"> and have the javascript: URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts href for anchors and then triggers a click inside an iframe, showing that the sanitized payload executes despite the protocol bypass.

Impact

Predicate-based allowlisting bypasses DOMPurify's URI validation, allowing unsafe protocols such as javascript: to reach the DOM and execute whenever the link is activated, resulting in DOM-based XSS.

Credits

Identified by Cantina’s Apex (https://www.cantina.security).

Versions of handlebars prior to 4.0.14 are vulnerable to Prototype Pollution. Templates may alter an Objects' prototype, thus allowing an attacker to execute arbitrary code on the server.

Recommendation

For handlebars 4.1.x upgrade to 4.1.2 or later. For handlebars 4.0.x upgrade to 4.0.14 or later.

DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. Attackers can supply a predicate that accepts specific attribute and tag combinations to bypass URI-safe validation, allowing unsafe protocols like javascript: to survive sanitization and execute as DOM-based XSS when the link is activated.

TuxCare rebuilt handlebars to address 1 CVE. Fixed in 1.3.0-tuxcare.1.

TuxCare rebuilt handlebars to address 3 CVEs. Fixed in 1.0.12-tuxcare.2.

TuxCare rebuilt dompurify to address 6 CVEs. Fixed in 3.1.6-tuxcare.3.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 3.2.3-tuxcare.1.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 3.0.3-tuxcare.1.

TuxCare rebuilt dompurify to address 9 CVEs. Fixed in 2.4.0-tuxcare.1.

TuxCare rebuilt dompurify to address 9 CVEs. Fixed in 2.4.7-tuxcare.1.

TuxCare rebuilt dompurify to address 1 CVE. Fixed in 3.0.3-tuxcare.4.

TuxCare rebuilt dompurify to address 3 CVEs. Fixed in 2.5.8-tuxcare.6.

TuxCare rebuilt dompurify to address 1 CVE. Fixed in 2.4.3-tuxcare.6.

TuxCare rebuilt dompurify to address 16 CVEs. Fixed in 2.4.0-tuxcare.1.

TuxCare rebuilt dompurify to address 14 CVEs. Fixed in 2.4.7-tuxcare.1.

TuxCare rebuilt dompurify to address 34 CVEs. Fixed in 3.0.3-tuxcare.1.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 2.0.8-tuxcare.3.

TuxCare rebuilt dompurify to address 12 CVEs. Fixed in 2.3.3-tuxcare.3.

TuxCare rebuilt dompurify to address 9 CVEs. Fixed in 3.2.6-tuxcare.3.

TuxCare rebuilt dompurify to address 13 CVEs. Fixed in 2.3.10-tuxcare.3.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 3.0.1-tuxcare.3.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 3.0.2-tuxcare.3.

TuxCare rebuilt dompurify to address 8 CVEs. Fixed in 3.0.8-tuxcare.3.

TuxCare rebuilt dompurify to address 9 CVEs. Fixed in 3.0.9-tuxcare.3.

TuxCare rebuilt dompurify to address 7 CVEs. Fixed in 3.0.11-tuxcare.3.

TuxCare rebuilt dompurify to address 6 CVEs. Fixed in 3.1.0-tuxcare.3.

TuxCare rebuilt dompurify to address 8 CVEs. Fixed in 3.1.3-tuxcare.3.

TuxCare rebuilt dompurify to address 10 CVEs. Fixed in 3.1.2-tuxcare.3.

TuxCare rebuilt dompurify to address 11 CVEs. Fixed in 3.1.1-tuxcare.3.

TuxCare rebuilt dompurify to address 8 CVEs. Fixed in 3.1.4-tuxcare.3.

Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to prototype pollution. It is possible to add or modify properties to the Object prototype through a malicious template. This may allow attackers to crash the application or execute Arbitrary Code in specific conditions.

Recommendation

Upgrade to version 3.0.8, 4.5.3 or later.

Versions of handlebars prior to 3.0.8 or 4.5.3 are vulnerable to Arbitrary Code Execution. The package's lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript in the system. It is due to an incomplete fix for a previous issue. This vulnerability can be used to run arbitrary code in a server processing Handlebars templates or on a victim's browser (effectively serving as Cross-Site Scripting).

Recommendation

Upgrade to version 3.0.8, 4.5.3 or later.

These are all security issues fixed in the velociraptor-0.76.7.0.git145.b60ef1146-1.1 package on the GA media of openSUSE Tumbleweed.

Root has patched CVE-2026-65912 in the dompurify package for Root:npm. Multiple fixed versions available.

Root has patched GHSA-2cf5-4w76-r9qv in the handlebars package for Root:npm. Multiple fixed versions available.

Root has patched GHSA-cjmm-f4jc-qw8r in the dompurify package for Root:npm. Multiple fixed versions available.

Root has patched GHSA-g9r4-xpmj-mj65 in the handlebars package for Root:npm. Multiple fixed versions available.

Root has patched GHSA-q2c6-c6pm-g3gh in the handlebars package for Root:npm. Multiple fixed versions available.

Root has patched GHSA-q42p-pg8m-cqh6 in the handlebars package for Root:npm. Multiple fixed versions available.