What is the CVSS score of CVE-2026-24116?

CVE-2026-24116 has a CVSS 3.1 base score of 5.5 (Medium). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of Wasmtime are affected by CVE-2026-24116?

Organizations using version 29.0.0 and should be aware of moderate risk from CVE-2026-24116, a out-of-bounds read vulnerability rated CVSS 5.5.. A patch is available.

How to fix or mitigate CVE-2026-24116?

Within 30 days: Identify affected systems running version 29.0.0 and and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Wasmtime CVE-2026-24116

MEDIUM

Out-of-bounds Read (CWE-125)

2026-01-27 security-advisories@github.com

GHSA-vc8c-j3xm-xj73

Buffer Overflow Information Disclosure Wasmtime

5.5

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.5 MEDIUM

AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

Patch released

Feb 12, 2026 - 21:36 nvd

Patch available

CVE Published

Jan 27, 2026 - 19:16 nvd

MEDIUM 5.5

DescriptionGitHub Advisory

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.

AnalysisAI

Wasmtime versions 29.0.0 through 41.0.0 on x86-64 platforms with AVX contain an out-of-bounds memory read in the f64.copysign instruction compilation that can cause application crashes when signal-based traps are disabled. In configurations with disabled guard pages, this vulnerability could potentially leak out-of-sandbox data, though the data remains inaccessible to WebAssembly guests without additional Cranelift bugs. Patches are available in versions 36.0.5, 40.0.3, and 41.0.1.

Technical ContextAI

Classified as CWE-125 (Out-of-bounds Read). Affects Wasmtime. 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 i