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CVE-2026-24116

CVE-2026-24116 · Wasmtime segfault or unused out-of-sandbox load with f64.copysign operator on x86-64

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Wasmtime is a runtime for WebAssembly. Starting in version 29.0.0 and prior to version 36.0.5, 40.0.3, and 41.0.1, on x86-64 platforms with AVX, Wasmtime's compilation of the `f64.copysign` WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can result in a uncaught segfault due to loading from unmapped guard pages. With guard pages disabled it's possible for out-of-sandbox data to be loaded, but unless there is another bug in Cranelift this data is not visible to WebAssembly guests. Wasmtime 36.0.5, 40.0.3, and 41.0.1 have been released to fix this issue. Users are recommended to upgrade to the patched versions of Wasmtime. Other affected versions are not patched and users should updated to supported major version instead. This bug can be worked around by enabling signals-based-traps. While disabling guard pages can be a quick fix in some situations, it's not recommended to disabled guard pages as it is a key defense-in-depth measure of Wasmtime.

CVSS 4.1 · Medium · EPSS 0.2% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • wasmtime

    Versions
    • >= 29.0.0, < 36.0.5: Affected
    • >= 37.0.0, < 40.0.3: Affected
    • = 41.0.0: Affected

    No fix published

  • rust-wasmtime Debian:14

    Versions
    • 26.0.1+dfsg-10
    • 26.0.1+dfsg-3
    • 26.0.1+dfsg-4
    • 26.0.1+dfsg-5
    • 26.0.1+dfsg-6
    • 26.0.1+dfsg-7
    • 26.0.1+dfsg-8
    • 26.0.1+dfsg-9
    • 27.0.0+dfsg-2
    • 27.0.0+dfsg-3
    • 27.0.0+dfsg-4
    • 28.0.1+dfsg-1
    • 28.0.1+dfsg-2
    • 28.0.1+dfsg-3
    • 29.0.1+dfsg-1
    • 29.0.1+dfsg-2
    • 29.0.1+dfsg-3
    • 29.0.1+dfsg-4
    • 29.0.1+dfsg-5
    • 29.0.1+dfsg-6
    • 29.0.1+dfsg-7
    • 29.0.1+dfsg-8
    Affected ranges
    • ECOSYSTEM: < 36.0.5+dfsg-1

    Update to 36.0.5+dfsg-1

  • rust-wasmtime Ubuntu:24.04:LTS

    Versions
    • 10.0.1+dfsg-7
    • 15.0.1+dfsg-4
    • 16.0.0+dfsg-2
    • 16.0.0+dfsg-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rust-wasmtime Ubuntu:25.10

    Versions
    • 26.0.1+dfsg-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rust-wasmtime Ubuntu:26.10

    Versions
    • 36.0.5+dfsg-1
    • 36.0.13+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rust-wasmtime Ubuntu:26.04:LTS

    Versions
    • 26.0.1+dfsg-3
    • 26.0.1+dfsg-4
    • 28.0.1+dfsg-3
    • 29.0.1+dfsg-5
    • 36.0.5+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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