CVE-2026-90648
Description
A flaw was found in wasm2c, a WebAssembly tool. This vulnerability, also known as a "table flip" attack, occurs when wasm2c fails to properly handle memory allocation failures for its function reference table. An attacker, by triggering this allocation failure, can bypass security boundaries, leading to arbitrary read and write of host process memory. This can further enable arbitrary code execution, effectively allowing a full sandbox escape and compromising the isolation provided by wasm2c.
Statement
This vulnerability is rated as Important because escaping in-process sandboxing compromises host application integrity and enables arbitrary code execution within the host context, rather than causing only a denial of service. In standard Red Hat Enterprise Linux 64-bit deployments with default virtual memory overcommit settings, triggering the flaw is difficult because allocations succeed unless the system experiences extreme memory exhaustion or strict address-space limits. Nonetheless, applications utilizing this runtime to isolate untrusted input remain vulnerable to complete boundary escapes if those memory constraints are met.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
