CVE-2026-34943 | bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0 WIT Interface uncaught exception (GHSA-m758-wjhj-p3jq)

VDB-356666 · CVE-2026-34943 · GHSA-M758-WJHJ-P3JQ BYTECODEALLIANCE WASMTIME UP TO 24.0.6/36.0.6/42.0.1/44.0.0 WIT INTERFACE UNCAUGHT EXCEPTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 2.1 $0-$5k 0.84 Summaryinfo A vulnerability, which was classified as problematic, was found in bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0. This affects an unknown part of the component WIT Interface. Such manipulation leads to uncaught exception. This vulnerability is documented as CVE-2026-34943. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component. Detailsinfo A vulnerability was found in bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0 and classified as problematic. Affected by this issue is some unknown functionality of the component WIT Interface. The manipulation with an unknown input leads to a uncaught exception vulnerability. Using CWE to declare the problem leads to CWE-248. An exception is thrown from a function, but it is not caught. Impacted is availability. CVE summarizes: Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1. The advisory is available at github.com. This vulnerability is handled as CVE-2026-34943 since 03/31/2026. The exploitation is known to be difficult. The attack may be launched remotely. The exploitation needs additional levels of successful authentication. The technical details are unknown and an exploit is not available. Upgrading to version 24.0.7, 36.0.7, 42.0.2 or 44.0.1 eliminates this vulnerability. Productinfo Vendor bytecodealliance Name wasmtime Version 24.0.0 24.0.1 24.0.2 24.0.3 24.0.4 24.0.5 24.0.6 36.0.0 36.0.1 36.0.2 36.0.3 36.0.4 36.0.5 36.0.6 42.0.0 42.0.1 44.0 Website Product: https://github.com/bytecodealliance/wasmtime/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA CVSS-B Score: 🔒 CNA CVSS-BT Score: 🔒 CNA Vector: 🔒 CVSSv3info VulDB Meta Base Score: 2.2 VulDB Meta Temp Score: 2.1 VulDB Base Score: 2.2 VulDB Temp Score: 2.1 VulDB Vector: 🔒 VulDB Reliability: 🔍 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: Uncaught exception CWE: CWE-248 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: wasmtime 24.0.7/36.0.7/42.0.2/44.0.1 Timelineinfo 03/31/2026 CVE reserved 04/09/2026 +9 days Advisory disclosed 04/09/2026 +0 days VulDB entry created 04/09/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-m758-wjhj-p3jq Status: Confirmed CVE: CVE-2026-34943 (🔒) GCVE (CVE): GCVE-0-2026-34943 GCVE (VulDB): GCVE-100-356666 Entryinfo Created: 04/09/2026 22:04 Changes: 04/09/2026 22:04 (67) Complete: 🔍 Cache ID: 99:7A5:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸