CVE-2026-115892
Wasmtime: Panic lowering a host-created component model stream into a guest that expects a different payload type
- State
- Published
- Severity
- 5.7 Medium
- Published
- Oct 23, 2026
- Updated
- Oct 29, 2026
- Reserved
- Oct 23, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.7 Medium | CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
wasmtimebytecodealliance |
|
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9pvw-hwfg-92h5
- https://github.com/bytecodealliance/wasmtime/pull/14819
- https://github.com/bytecodealliance/wasmtime/pull/14820
- https://github.com/bytecodealliance/wasmtime/pull/14827
- https://github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd
- https://github.com/bytecodealliance/wasmtime/commit/48dacc76241f06088e79f3ce1b17642f2f7bf158
- https://github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618
- https://github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7
- https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.