CVE-2026-34943

MEDIUM EPSS 24.1%
Published Apr 9, 20262mo ago · Modified Jun 17, 20261w ago
5.6 CVSS 4.0
Medium
Find Similar
Published Apr 9, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
5.6
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity High
Privileges Required High
User Interaction A
Scope X

Threat Intelligence

EPSS Exploit Probability
24.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-248

Affected Products 4

VendorProductVersionRange
bytecodealliancewasmtime* <24.0.7
bytecodealliancewasmtime*≥25.0.0  –  <36.0.7
bytecodealliancewasmtime*≥37.0.0  –  <42.0.2
bytecodealliancewasmtime*≥43.0.0  –  <43.0.1

References 1

  • github.com https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m758-wjhj-p3jq
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.