CVE-2026-34946 | bytecodealliance wasmtime up to 36.0.6/42.0.1/44.0.0 control flow (GHSA-q49f-xg75-m9xw)

VDB-356663 · CVE-2026-34946 · GHSA-Q49F-XG75-M9XW BYTECODEALLIANCE WASMTIME UP TO 36.0.6/42.0.1/44.0.0 CONTROL FLOW HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.1 $0-$5k 1.05 Summaryinfo A vulnerability classified as problematic has been found in bytecodealliance wasmtime up to 36.0.6/42.0.1/44.0.0. Affected is an unknown function. The manipulation leads to control flow. This vulnerability is listed as CVE-2026-34946. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component. Detailsinfo A vulnerability, which was classified as problematic, has been found in bytecodealliance wasmtime up to 36.0.6/42.0.1/44.0.0. This issue affects some unknown processing. The manipulation with an unknown input leads to a control flow vulnerability. Using CWE to declare the problem leads to CWE-670. The code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated. Impacted is availability. The summary by CVE is: Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a vulnerability where the compilation of the table.fill instruction can result in a host panic. This means that a valid guest can be compiled with Winch, on any architecture, and cause the host to panic. This represents a denial-of-service vulnerability in Wasmtime due to guests being able to trigger a panic. The specific issue is that a historical refactoring changed how compiled code referenced tables within the table.* instructions. This refactoring forgot to update the Winch code paths associated as well, meaning that Winch was using the wrong indexing scheme. Due to the feature support of Winch the only problem that can result is tables being mixed up or nonexistent tables being used, meaning that the guest is limited to panicking the host (using a nonexistent table), or executing spec-incorrect behavior and modifying the wrong table. This vulnerability is fixed in 36.0.7, 42.0.2, and 43.0.1. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-34946 since 03/31/2026. The exploitation is known to be easy. The attack may be initiated remotely. The technical details are unknown and an exploit is not publicly available. Upgrading to version 36.0.7, 42.0.2 or 44.0.1 eliminates this vulnerability. Productinfo Vendor bytecodealliance Name wasmtime Version 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: Control flow CWE: CWE-670 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 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-q49f-xg75-m9xw Status: Confirmed CVE: CVE-2026-34946 (🔒) GCVE (CVE): GCVE-0-2026-34946 GCVE (VulDB): GCVE-100-356663 Entryinfo Created: 04/09/2026 22:04 Changes: 04/09/2026 22:04 (66) Complete: 🔍 Cache ID: 99:7B3:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸