CVE-2026-115889

CVE Enrichment

CVSS: 9.9 CRITICAL
EPSS: 0.45%
EPSS Percentile: 39.16%
CISA KEV: Not listed

Description

Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: [email protected]
Published: 24-Oct-2026 05:16
Last Modified: 27-Oct-2026 01:17
EPSS Date: 2026-10-26
CWE: CWE-197, CWE-843

CVSS Vector


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

References

Last enrichment sync: 27-Oct-2026 02:16
Sources: NVD · FIRST EPSS · CISA KEV
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Reported Context (3)

CVE-2026-115889 – Wasmtime CYFIRMA’s Fortnightly Exploit Radar Highlights Five Vulnerabilities
Two critical Wasmtime sandbox escape flaws, CVE-2026-115889 and CVE-2026-115893, let a crafted WebAssembly (Wasm) module push the Cranelift compiler into generating unsafe machine code. Critical Wasmtime Flaws Could Enable WebAssembly Sandbox Escapes
As of October 26, GitHub's advisory database had a reviewed entry for CVE-2026-115889 but none for CVE-2026-115893. GitHub says only reviewed entries trigger Dependabot alerts, so Dependabot users should not expect an Two Critical Wasmtime Flaws Could Enable WebAssembly Sandbox Escape

CVE (6)

People (2)

Vendors (3)

Products (6)

Tools (2)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.