CVE-2026-33490 | h3js h3 up to 2.0.0-0/2.0.1-rc.16/2.0.2-rc.17 mount name resolution

VDB-353686 · CVE-2026-33490 · GCVE-0-2026-33490 H3JS H3 UP TO 2.0.0-0/2.0.1-RC.16/2.0.2-RC.17 MOUNT NAME RESOLUTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 3.8 $0-$5k 1.63+ Summaryinfo A vulnerability was found in h3js h3 up to 2.0.0-0/2.0.1-rc.16/2.0.2-rc.17 and classified as problematic. This vulnerability affects the function mount. Executing a manipulation can lead to name resolution. This vulnerability is handled as CVE-2026-33490. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component. Detailsinfo A vulnerability has been found in h3js h3 up to 2.0.0-0/2.0.1-rc.16/2.0.2-rc.17 and classified as problematic. This vulnerability affects the function mount. The manipulation with an unknown input leads to a name resolution vulnerability. The CWE definition for the vulnerability is CWE-706. The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes: 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. The advisory is available at github.com. This vulnerability was named CVE-2026-33490 since 03/20/2026. The exploitation appears to be difficult. The attack can be initiated remotely. The exploitation needs additional levels of successful authentication. Technical details are known, but there is no available exploit. Upgrading to version 2.0.1-rc.17 eliminates this vulnerability. Productinfo Vendor h3js Name h3 Version 2.0 2.0.1-rc.0 2.0.1-rc.1 2.0.1-rc.2 2.0.1-rc.3 2.0.1-rc.4 2.0.1-rc.5 2.0.1-rc.6 2.0.1-rc.7 2.0.1-rc.8 2.0.1-rc.9 2.0.1-rc.10 2.0.1-rc.11 2.0.1-rc.12 2.0.1-rc.13 2.0.1-rc.14 2.0.1-rc.15 2.0.1-rc.16 2.0.2-rc.0 2.0.2-rc.1 2.0.2-rc.2 2.0.2-rc.3 2.0.2-rc.4 2.0.2-rc.5 2.0.2-rc.6 2.0.2-rc.7 2.0.2-rc.8 2.0.2-rc.9 2.0.2-rc.10 2.0.2-rc.11 2.0.2-rc.12 2.0.2-rc.13 2.0.2-rc.14 2.0.2-rc.15 2.0.2-rc.16 2.0.2-rc.17 Website Product: https://github.com/h3js/h3/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 3.9 VulDB Meta Temp Score: 3.8 VulDB Base Score: 4.1 VulDB Temp Score: 3.9 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 3.7 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Name resolution CWE: CWE-706 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: h3 2.0.1-rc.17 Timelineinfo 03/20/2026 CVE reserved 03/26/2026 +6 days Advisory disclosed 03/26/2026 +0 days VulDB entry created 03/26/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Status: Confirmed CVE: CVE-2026-33490 (🔒) GCVE (CVE): GCVE-0-2026-33490 GCVE (VulDB): GCVE-100-353686 Entryinfo Created: 03/26/2026 19:02 Changes: 03/26/2026 19:02 (63) Complete: 🔍 Cache ID: 99:685:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸