CVE-2026-115383

Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports

MEDIUM
4.8
CVSS Score
Published: October 22, 2026 at 07:13 PM UTC
Updated: October 22, 2026 at 07:17 PM UTC
1 product affected across 1 vendorWasmtime

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 48.0.4 (unaffected)
Vendor states this is fixed in 49.0.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

4.8MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-1287

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