CVE-2026-31873

Unhead suffers a bypass of URI scheme sanitization in makeTagSafe prior to version 2.1.11: the code checks href values with String.includes(), which is case-sensitive. Since browsers treat URI schemes case-insensitively, inputs like DATA:text/css,... can evade the check and allow arbitrary CSS vi...

CVE-2026-31873 Unhead has a Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity

Unhead is a document head and template manager. Prior to 2.1.11, The link.href check in makeTagSafe safe.ts uses String.includes, which is case-sensitive. Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as data:text/css,... to the browser, but 'DATA:...'.includes'data...

CVE-2026-31873 Unhead has a Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity

Unhead is a document head and template manager. Prior to 2.1.11, The link.href check in makeTagSafe safe.ts uses String.includes, which is case-sensitive. Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as data:text/css,... to the browser, but 'DATA:...'.includes'data...

Unhead Vulnerable to Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity

The link.href check in makeTagSafe safe.ts, line 68-71 uses String.includes, which is case-sensitive: typescript if key === 'href' if val.includes'javascript:' || val.includes'data:' return nextkey = val Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as...

EUVD-2026-11640

Unhead Vulnerable to Bypass of URI Scheme Sanitization in makeTagSafe via Case-Sensitivity...