CVE-2026-33490

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Source
https://cve.org/CVERecord?id=CVE-2026-33490
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33490.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-33490
Aliases
Published
2026-03-26T17:19:15.956Z
Modified
2026-04-02T13:27:32.821277Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
Summary
h3: Missing Path Segment Boundary Check in `mount()` Causes Middleware Execution on Unrelated Prefix-Matching Routes
Details

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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33490.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-706"
    ]
}
References

Affected packages

Git / github.com/h3js/h3

Affected ranges

Type
GIT
Repo
https://github.com/h3js/h3
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
388b8f06e060a219d11bbc6be7f70f38d8bbea01
Database specific 
{
    "versions": [
        {
            "introduced": "2.0.1-alpha.0"
        },
        {
            "fixed": "2.0.1-rc.17"
        }
    ]
}

Affected versions

v0.*
v0.0.1
v0.0.10
v0.0.11
v0.0.12
v0.0.13
v0.0.14
v0.0.15
v0.0.2
v0.0.3
v0.0.4
v0.0.5
v0.0.6
v0.0.7
v0.0.8
v0.0.9
v0.2.0
v0.2.1
v0.2.10
v0.2.11
v0.2.12
v0.2.2
v0.2.3
v0.2.4
v0.2.5
v0.2.6
v0.2.7
v0.2.8
v0.2.9
v0.3.0
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.3.6
v0.3.7
v0.3.8
v0.3.9
v0.4.0
v0.4.1
v0.4.2
v0.5.0
v0.5.1
v0.5.2
v0.5.3
v0.5.4
v0.5.5
v0.5.6
v0.5.7
v0.6.0
v0.7.0
v0.7.1
v0.7.10
v0.7.11
v0.7.12
v0.7.13
v0.7.14
v0.7.15
v0.7.16
v0.7.17
v0.7.18
v0.7.19
v0.7.2
v0.7.20
v0.7.21
v0.7.3
v0.7.4
v0.7.5
v0.7.6
v0.7.7
v0.7.8
v0.7.9
v0.8.0
v0.8.1
v0.8.2
v0.8.3
v0.8.4
v0.8.5
v0.8.6
v1.*
v1.0.0
v1.0.1
v1.0.2
v1.1.0
v1.10.0
v1.10.1
v1.10.2
v1.11.0
v1.11.1
v1.12.0
v1.13.0
v1.13.1
v1.14.0
v1.15.0
v1.15.1
v1.15.10
v1.15.11
v1.15.2
v1.15.3
v1.15.4
v1.15.5
v1.15.6
v1.15.7
v1.15.8
v1.15.9
v1.2.0
v1.2.1
v1.3.0
v1.4.0
v1.5.0
v1.6.0
v1.6.1
v1.6.2
v1.6.3
v1.6.4
v1.6.5
v1.6.6
v1.7.0
v1.7.1
v1.8.0
v1.8.0-rc.0
v1.8.0-rc.1
v1.8.0-rc.2
v1.8.0-rc.3
v1.8.1
v1.8.2
v1.9.0
v2.*
v2.0.0-beta.0
v2.0.0-beta.1
v2.0.0-beta.2
v2.0.0-beta.3
v2.0.0-beta.4
v2.0.0-beta.5
v2.0.0-rc.1
v2.0.1-rc.10
v2.0.1-rc.11
v2.0.1-rc.12
v2.0.1-rc.13
v2.0.1-rc.14
v2.0.1-rc.15
v2.0.1-rc.16
v2.0.1-rc.2
v2.0.1-rc.3
v2.0.1-rc.4
v2.0.1-rc.5
v2.0.1-rc.6
v2.0.1-rc.7
v2.0.1-rc.8
v2.0.1-rc.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33490.json"