Low severity · published Oct 29, 2026
CVE-2026-119133
Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags
New
2.6
CVSS
–
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WA
wasmtime · bytecodealliance
47.0.0 before 48.0.6; 49.0.0 before 49.0.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-119133
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-119133
vendor-advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p79w-pv2r-29qp
third-party-advisory
https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.6-and-49.0.0-before-49.0.3-misaligned-vmcontext-via-exception-tags
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