Critical severity · published Oct 22, 2026
CVE-2026-115384
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
New
9.9
CVSS
0.3%
EPSS
No
On KEV
Description
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WA
wasmtime · bytecodealliance
39.0.0 before 48.0.4; 49.0.0 before 49.0.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-115384
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-115384
github.com
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c
www.vulncheck.com
https://www.vulncheck.com/advisories/wasmtime-39.0.0-before-48.0.4-and-49.0.0-before-49.0.2-stack-buffer-overflow
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