Out-of-bounds Read in Bytecodealliance Wasmtime
CVE-2026-34971
Wasmtime is a runtime for WebAssembly. From 32.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Cranelift compilation backend contains a bug on aarch64 when performing a certain shape of heap accesses which means that the wrong address…
Vulnerability class: Buffer Overflow
EPSS: 0.003 (24.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Bytecodealliance Wasmtime — versions 43.0.0, >= 32.0.0, < 36.0.7, >= 43.0.0, < 44.0.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-34971?
- CVE-2026-34971 is a high-severity vulnerability in Bytecodealliance Wasmtime, classified under Out-of-bounds Read. CVSS score: 7.8/10. Published 2026-04-09.
- How severe is CVE-2026-34971?
- High severity. CVSS v3 base score is 7.8 out of 10.