CVE-2026-35195 | bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0 out-of-bounds write (GHSA-394w-hwhg-8vgm)

VDB-356672 · CVE-2026-35195 · GHSA-394W-HWHG-8VGM BYTECODEALLIANCE WASMTIME UP TO 24.0.6/36.0.6/42.0.1/44.0.0 OUT-OF-BOUNDS WRITE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.0 $0-$5k 1.37 Summaryinfo A vulnerability categorized as critical has been discovered in bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0. This affects an unknown function. Such manipulation leads to out-of-bounds write. This vulnerability is uniquely identified as CVE-2026-35195. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component. Detailsinfo A vulnerability, which was classified as critical, has been found in bytecodealliance wasmtime up to 24.0.6/36.0.6/42.0.1/44.0.0. Affected by this issue is an unknown functionality. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and 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 between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This enables a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary location up to 4GiB away from the base of linear memory. These writes on the host could hit unmapped memory or could corrupt host data structures depending on Wasmtime's configuration. Wasmtime by default reserves 4GiB of virtual memory for a guest's linear memory meaning that this bug will by default on hosts cause the host to hit unmapped memory and abort the process due to an unhandled fault. Wasmtime can be configured, however, to reserve less memory for a guest and to remove all guard pages, so some configurations of Wasmtime may lead to corruption of data outside of a guest's linear memory, such as host data structures or other guests's linear memories. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-35195 since 04/01/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly 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: 6.3 VulDB Meta Temp Score: 6.0 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 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: Out-of-bounds write CWE: CWE-787 / 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 04/01/2026 CVE reserved 04/09/2026 +8 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-394w-hwhg-8vgm Status: Confirmed CVE: CVE-2026-35195 (🔒) GCVE (CVE): GCVE-0-2026-35195 GCVE (VulDB): GCVE-100-356672 Entryinfo Created: 04/09/2026 22:05 Changes: 04/09/2026 22:05 (67) Complete: 🔍 Cache ID: 99:528:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸