Bytecode Alliance Wasmtime up to 48.0.3/49.0.1 heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.1$0-$5k0.82

Summaryinfo

A vulnerability categorized as problematic has been discovered in Bytecode Alliance Wasmtime up to 48.0.3/49.0.1. This issue affects some unknown processing. Executing a manipulation can lead to heap-based overflow. This vulnerability is registered as CVE-2026-115383. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Bytecode Alliance Wasmtime up to 48.0.3/49.0.1. This vulnerability affects an unknown functionality. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-115383 since 10/22/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

Upgrading to version 48.0.4 or 49.0.2 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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: 4.1
VulDB Meta Temp Score: 4.1

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

CNA Base Score: 4.8
CNA Vector (VulnCheck): 🔒

CVSSv2info

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

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
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 48.0.4/49.0.2

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-2026-115383 (🔒)
GCVE (CVE): GCVE-0-2026-115383
GCVE (VulDB): GCVE-100-425440

Entryinfo

Created: 10/22/2026 22:19
Changes: 10/22/2026 22:19 (75)
Complete: 🔍
Cache ID: 216::103

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