CVE-2026-34942 | bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0 array index (GHSA-jxhv-7h78-9775)

VDB-356650 · CVE-2026-34942 · GHSA-JXHV-7H78-9775 BYTECODEALLIANCE WASMTIME UP TO 24.0.6/36.0.6/42.0.1/44.0.0 ARRAY INDEX HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.1 $0-$5k 0.47+ Summaryinfo A vulnerability 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 function. Executing a manipulation can lead to array index. This vulnerability is registered as CVE-2026-34942. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised. Detailsinfo A vulnerability was found in bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0. It has been declared as problematic. This vulnerability affects an unknown function. The manipulation with an unknown input leads to a array index vulnerability. The CWE definition for the vulnerability is CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. As an impact it is known to affect 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's implementation of transcoding strings into the Component Model's utf16 or latin1+utf16 encodings improperly verified the alignment of reallocated strings. This meant that unaligned pointers could be passed to the host for transcoding which would trigger a host panic. This panic is possible to trigger from malicious guests which transfer very specific strings across components with specific addresses. Host panics are considered a DoS vector in Wasmtime as the panic conditions are controlled by the guest in this situation. 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 was named CVE-2026-34942 since 03/31/2026. The exploitation appears to be easy. The attack can be initiated remotely. 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: 4.3 VulDB Meta Temp Score: 4.1 VulDB Base Score: 4.3 VulDB Temp Score: 4.1 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: Array index CWE: CWE-129 / CWE-119 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-jxhv-7h78-9775 Status: Confirmed CVE: CVE-2026-34942 (🔒) GCVE (CVE): GCVE-0-2026-34942 GCVE (VulDB): GCVE-100-356650 Entryinfo Created: 04/09/2026 21:36 Changes: 04/09/2026 21:36 (66) Complete: 🔍 Cache ID: 99:052:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸