Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
History

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Description Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
Title Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports
First Time appeared Bytecodealliance
Bytecodealliance wasmtime
Weaknesses CWE-1287
CWE-843
CPEs cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*
Vendors & Products Bytecodealliance
Bytecodealliance wasmtime
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 5.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

threat_severity

Moderate


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-10-22T19:13:50.687Z

Updated: 2026-10-22T19:13:50.687Z

Reserved: 2026-10-22T11:25:27.610Z

Link: CVE-2026-115383

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-10-22T19:17:45.387

Modified: 2026-10-22T19:17:45.500

Link: CVE-2026-115383

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-22T19:13:50Z

Links: CVE-2026-115383 - Bugzilla