CVE-2026-33490
H3 is a minimal H(TTP) framework.
Published Mar 26, 2026 · updated Jun 17, 2026 · h3 h3
H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the method in h3 uses a simple 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 will also execute for unrelated routes such as , , or . 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.
Code
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No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 26, 2026 · NIST NVD
Detected
H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the method in h3 uses a simple 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 will also execute for unrelated
Jun 17, 2026 · NIST NVD
Updated
H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the method in h3 uses a simple 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 will also execute for unrelated
Affected
- cpe h3/h32.0.1
Sources
- CVE.orgVulnerability recordCVE-2026-33490
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-33490
H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the method in h3 uses a simple check to determine whether incoming requests fall under a mounted sub-application's path prefix. Because this check does not verify a path segment bo
nvd.nist.gov