CVE-2026-115383: Improper Validation of Specified Type of Input in bytecodealliance wasmtime
Description
Wasmtime versions 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 have an improper validation vulnerability related to WebAssembly tags with subtypes. This flaw allows malicious guests to mis-type exception object payloads, potentially corrupting the garbage-collected heap and causing Wasmtime to panic when the exceptions proposal is enabled.
CVSS v4.0
Score 5.9medium
Affected software
bytecodealliance
wasmtime
pkg:cargo/github/bytecodealliance/wasmtimeRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-115383 affects Wasmtime versions >=47.0.0 <48.0.4 and >=49.0.0 <49.0.2. The vulnerability arises from improper validation of components whose core modules import WebAssembly tags with a subtype of the original type. This allows malicious guests to mis-type exception object payloads, leading to corruption of the garbage-collected heap and causing Wasmtime to panic when the exceptions proposal feature is enabled.
Potential Impact
Exploitation of this vulnerability can cause Wasmtime to panic due to heap corruption when processing mis-typed exception payloads. This may disrupt normal operation but does not indicate remote code execution or data leakage. The CVSS score of 5.9 reflects a medium severity with potential partial impact on availability or integrity.
Mitigation Recommendations
Fixed versions are available: upgrade to Wasmtime 48.0.4 or later, or 49.0.2 or later. Users should update to these versions to remediate the vulnerability. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-22T11:25:27.610Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ada64a34d27ba8daa756575
Added to database: 10/22/2026, 19:31:47 UTC
Last enriched: 10/22/2026, 20:31:19 UTC
Last updated: 10/22/2026, 21:15:28 UTC
Views: 3
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