CVE-2026-44216
Wasmtime: Panic when allocating a table exceeding the size of the host's address space
- State
- Published
- Severity
- 5.9 Medium
- Published
- May 14, 2026
- Updated
- Jul 28, 2026
- Reserved
- May 5, 2026
Description
Wasmtime is a runtime for WebAssembly. From 30.0.0 to 36.0.8, 43.0.2, and 44.0.1, Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables can have sizes in the 64-bit range as opposed to the previous 32-bit range which would not overflow. The panic happens when attempting to create a very large table, such as when instantiating a WebAssembly module or component. This vulnerability is fixed in 36.0.8, 43.0.2, and 44.0.1.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.9 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | GitHub_M |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
wasmtimebytecodealliance |
|
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p8xm-42r7-89xg
- https://access.redhat.com/security/cve/CVE-2026-44216vdb-entry
- RHBZ#2477467issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44216.json
- https://access.redhat.com/errata/RHSA-2026:45341vendor-advisory
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