PatchTheCEVCVE-2026-115893: Wasmtime is a runtime for WebAssembly
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This month
CRITICAL 9.9
CVE-2026-115893 is a critical-severity flaw (CVSS 9.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. The branch can then jump to arbitrary other code at a user-controlled offset, allowing a user-controlled Wasm module to escape the sandbox on aarch64 engines using the default Cranelift backe
Why this priority
- Critical severity
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 9.9 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-691 |
| Published | 2026-10-23 |
| Last modified | 2026-10-23 |
Publisher (CNA): GitHub, Inc.
Timeline
- Published CVE record published
- Updated Record last modified
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.