CVE-2026-119139
Description
A flaw was found in Wasmtime. An attacker who supplies a crafted WebAssembly component can cause a Denial of Service (DoS) by crashing the host application. This issue occurs because an internal assertion fails when the host invokes an exported guest function configured with asynchronous Application Binary Interface (ABI) options.
Statement
This vulnerability is rated as Moderate impact because successful exploitation is limited to terminating the host process, without enabling unauthorized privilege escalation or data confidentiality compromise. In supported Red Hat offerings, exposing this flaw requires an embedding service to load and execute asynchronous exported functions from untrusted WebAssembly modules. Environments where WebAssembly workloads originate exclusively from verified, trusted sources are not at risk from this denial of service condition.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.8 | N/A | 4.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, an attacker can still cause a denial of service if they can trigger an assert statement, and if the scope of the assert() extends beyond the attacker's own session. For example, if a server handles multiple simultaneous connections, if an assert() occurs in one single connection that causes all other connections to be dropped, this could be a significant denial of service.
Frequently Asked Questions
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