CVE-2026-34942
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
52/100
Published: 2026-04-09
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
Passive
S:
X
AT:
Present
VC:
None
VI:
None
VA:
High
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.
Weakness Classification (1)
Affected Software (4)
| Vendor | Product | Version |
|---|---|---|
| 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 |
References & Advisories (1)
Vendor Advisory