CVE-2026-33131 is a critical Host header spoofing vulnerability affecting H3 framework versions 2.0.0-0 through 2.0.1-rc.14, including applications built on Nitro/Nuxt that access event.url properties in middleware. This flaw allows an unauthenticated attacker to craft a malicious Host header, bypassing authentication or authorization middleware and gaining unauthorized access to sensitive routes. Rated 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N), it poses a high risk to confidentiality and integrity due to its network-based, low-complexity attack vector. There is currently no evidence of active exploitation, nor are public exploit codes available, and community discussion remains very low. A patch is available in version 2.0.1-rc.15.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
2.0.0CPE matchmatch criteria | cpe:2.3:a:h3:h3:2.0.0:*:*:*:*:node.js:*:* | ||
2.0.1CPE matchmatch criteria | cpe:2.3:a:h3:h3:2.0.1:rc10:*:*:*:node.js:*:* | ||
2.0.1CPE matchmatch criteria | cpe:2.3:a:h3:h3:2.0.1:rc11:*:*:*:node.js:*:* | ||
2.0.1CPE matchmatch criteria | cpe:2.3:a:h3:h3:2.0.1:rc12:*:*:*:node.js:*:* | ||
2.0.1CPE matchmatch criteria | cpe:2.3:a:h3:h3:2.0.1:rc13:*:*:*:node.js:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.