VDB-428644 · CVE-2026-119133 · Nessus 374255

Bytecode Alliance Wasmtime up to 48.0.5/49.0.2 VMContext layout memory corruption

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4.0	$0-$5k	0.80

Summaryinfo

A vulnerability was found in Bytecode Alliance Wasmtime up to 48.0.5/49.0.2. It has been declared as critical. The impacted element is an unknown function of the component VMContext layout. Executing a manipulation can lead to memory corruption. The identification of this vulnerability is CVE-2026-119133. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Bytecode Alliance Wasmtime up to 48.0.5/49.0.2. This vulnerability affects some unknown processing of the component VMContext layout. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-119133 since 10/29/2026. 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.

The vulnerability scanner Nessus provides a plugin with the ID 374255 (Linux Distros Unpatched Vulnerability : CVE-2026-119133), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 48.0.6 or 49.0.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (374255). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Bytecode Alliance

Name

Wasmtime

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: 4.0

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 2.6
CNA Vector (VulnCheck): 🔒

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 374255
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-119133

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Wasmtime 48.0.6/49.0.3

Timelineinfo

10/29/2026 Advisory disclosed
10/29/2026 +0 days CVE reserved
10/29/2026 +0 days VulDB entry created
10/30/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CNA: VulnCheck
CVE: CVE-2026-119133 (🔒)

GCVE (CVE): GCVE-0-2026-119133
GCVE (VulDB): GCVE-100-428644

Entryinfo

Created: 10/29/2026 17:20
Updated: 10/30/2026 22:58
Changes: 10/29/2026 17:20 (76), 10/30/2026 22:58 (2)
Complete: 🔍
Cache ID: 216::103