CVEvulnerability
CVE-2026-34942
5.9 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-04-09
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 5.9 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-129
Description
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.
Affected configurations
• bytecodealliance wasmtime (< 24.0.7)
• bytecodealliance wasmtime (>= 25.0.0 < 36.0.7)
• bytecodealliance wasmtime (>= 37.0.0 < 42.0.2)
• bytecodealliance wasmtime (>= 43.0.0 < 43.0.1)
Related
Weakness · CWE (1)
- CWE-129 Improper Validation of Array Index weakness