Vulnerability in Bytecodealliance Wasmtime
CVE-2026-119133
Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.6 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p79w-pv2r-29qp (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.6-and-49.0.0-before-49… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-119133?
- CVE-2026-119133 is a low-severity vulnerability in Bytecodealliance Wasmtime, classified under CWE-758. CVSS score: 2.6/10. Published 2026-10-29.
- How severe is CVE-2026-119133?
- Low severity. CVSS v3 base score is 2.6 out of 10.