CVE-2026-33490
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
26/03/2026
Last modified:
31/03/2026
Description
H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the `mount()` method in h3 uses a simple `startsWith()` check to determine whether incoming requests fall under a mounted sub-application's path prefix. Because this check does not verify a path segment boundary (i.e., that the next character after the base is `/` or end-of-string), middleware registered on a mount like `/admin` will also execute for unrelated routes such as `/admin-public`, `/administrator`, or `/adminstuff`. This allows an attacker to trigger context-setting middleware on paths it was never intended to cover, potentially polluting request context with unintended privilege flags. Version 2.0.2-rc.17 contains a patch.
Impact
Base Score 3.x
3.70
Severity 3.x
LOW
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:h3:h3:2.0.1:rc1:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc10:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc11:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc12:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc13:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc14:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc15:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc16:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc2:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc3:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc4:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc5:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc6:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc7:*:*:*:node.js:*:* | ||
| cpe:2.3:a:h3:h3:2.0.1:rc8:*:*:*:node.js:*:* |
To consult the complete list of CPE names with products and versions, see this page