Out-of-bounds read in Wasmtime - CVE-2026-34941
Published: April 10, 2026
Vulnerability identifier: #VU125764
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-34941
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in the component model UTF-16 to latin1+utf16 string transcoding logic when processing cross-component string passing with UTF-16 source and latin1+utf16 destination encodings. A remote user can supply a crafted WebAssembly component string to cause a denial of service.
In the default configuration, exploitation causes the host process to crash with SIGBUS or SIGSEGV.
Affected software
Wasmtime
How to mitigate CVE-2026-34941
Install security update from vendor's website.
Wasmtime - addressed in versions 24.0.7, 36.0.7, 42.0.2, 43.0.1