Bug 2560223 (CVE-2026-115892)

Summary: CVE-2026-115892 wasmtime: Wasmtime: Denial of Service via missing payload type validation in guest returns
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Wasmtime. A malicious WebAssembly guest can cause a Denial of Service (DoS) by triggering an unhandled host runtime panic. When handling asynchronous streams or futures exchanged between the host and guest, Wasmtime fails to properly validate payload data types upon their return. An untrusted guest can exploit this behavior by manipulating return values with mismatched types, causing the host application to terminate unexpectedly.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-23 21:41:33 UTC 
Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or an equivalent typed reader. A malicious guest that controls exported function types or returned values can cause the host to pass the type-erased value to a guest expecting a different payload type, which panics the Wasmtime host. This issue is fixed in versions 48.0.7 and 49.0.4.