CVE-2026-33131

H3 is a minimal H(TTP) framework. Versions 2.0.0-0 through 2.0.1-rc.14 contain a Host header spoofing vulnerability in the NodeRequestUrl (which extends FastURL) which allows middleware bypass. When event.url, event.url.hostname, or event.url._url is accessed, such as in a logging middleware, the _url getter constructs a URL from untrusted data, including the user-controlled Host header. Because H3's router resolves the route handler before middleware runs, an attacker can supply a crafted Host header (e.g., Host: localhost:3000/abchehe?) to make the middleware path check fail while the route handler still matches, effectively bypassing authentication or authorization middleware. This affects any application built on H3 (including Nitro/Nuxt) that accesses event.url properties in middleware guarding sensitive routes. The issue requires an immediate fix to prevent FastURL.href from being constructed with unsanitized, attacker-controlled input. Version 2.0.1-rc.15 contains a patch for this issue.
References
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:h3:h3:2.0.0:*:*:*:*: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: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:*:*
cpe:2.3:a:h3:h3:2.0.1:rc9:*:*:*:node.js:*:*

History

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Information

Published : 2026-03-20 11:18

Updated : 2026-03-20 19:45


NVD link : CVE-2026-33131

Mitre link : CVE-2026-33131

CVE.ORG link : CVE-2026-33131


JSON object : View

Products Affected

h3

  • h3
CWE
CWE-290

Authentication Bypass by Spoofing