What’s Vulnerable › Vulnerabilities

CVE-2026-115393: Wasmtime before 24.0.12, 25.0.0 before 36.0.13, 37.0.0 before 46.0.2, and 47.0.0 before 47.0.3 Cross-Engine Type Confusion

• Severity: low (CVSS 3.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-22 · updated 2026-10-29
• Weakness: CWE-787

Description

Wasmtime before 24.0.12, 25.0.0 before 36.0.13, 37.0.0 before 46.0.2, and 47.0.0 before 47.0.3 contains a type confusion vulnerability because several Store APIs fail to validate that objects belong to the Store's Engine. Embedders mixing objects between Engines via Instance::new, StructRefPre::new, or Tag::new can trigger trampoline signature mismatches causing out-of-bounds stack writes, GC heap corruption, or panics.

Affected products

• bytecodealliance wasmtime: before 24.0.12; from 25.0.0 before 36.0.13; from 37.0.0 before 46.0.2; from 47.0.0 before 47.0.3 — fixed in 24.0.12, 36.0.13, 46.0.2, 47.0.3

How to fix

Upgrade to a fixed version: bytecodealliance wasmtime 24.0.12, 36.0.13, 46.0.2, 47.0.3. Check the vendor advisory for mitigations.

References

• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hgjw-h833-99q9
• https://www.vulncheck.com/advisories/wasmtime-before-24.0.12-25.0.0-before-36.0.13-37.0.0-before-46.0.2-and-47.0.0-before-47.0.3-cross-engine-type-confusion

Get alerted when CVE-2026-115393 or the next vulnerability affects your stack