Bytecode Alliance Wasmtime up to 36.0.15/48.0.2/49.0.0 Dynamically-typed Val API denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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2.8$0-$5k1.24

Summaryinfo

A vulnerability was found in Bytecode Alliance Wasmtime up to 36.0.15/48.0.2/49.0.0. It has been declared as problematic. This affects an unknown part of the component Dynamically-typed Val API. Such manipulation leads to denial of service. This vulnerability is listed as CVE-2026-115389. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Bytecode Alliance Wasmtime up to 36.0.15/48.0.2/49.0.0. It has been rated as problematic. Affected by this issue is some unknown processing of the component Dynamically-typed Val API. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-115389 since 10/22/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 36.0.16, 48.0.3 or 49.0.1 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 2.9
VulDB Meta Temp Score: 2.8

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 2.3
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Wasmtime 36.0.16/48.0.3/49.0.1

Timelineinfo

10/22/2026 Advisory disclosed
10/22/2026 +0 days CVE reserved
10/22/2026 +0 days VulDB entry created
10/22/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-115389 (🔒)
GCVE (CVE): GCVE-0-2026-115389
GCVE (VulDB): GCVE-100-425438

Entryinfo

Created: 10/22/2026 22:18
Changes: 10/22/2026 22:18 (76)
Complete: 🔍
Cache ID: 216::103

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