CVE-2026-34942
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
Summary
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 Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| bytecodealliance | wasmtime | < 24.0.7 | affected |
| bytecodealliance | wasmtime | >= 25.0.0, < 36.0.7 | affected |
| bytecodealliance | wasmtime | >= 37.0.0, < 42.0.2 | affected |
| bytecodealliance | wasmtime | >= 43.0.0, < 44.0.1 | affected |
Weaknesses
- CWE-129: CWE-129: Improper Validation of Array Index
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.