CVE-2026-109748

5.4Medium

Published 13 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash

5.4Medium

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Impact: Limited impact
Weakness: CWE-416

Impact

Remote attackers can trigger memory corruption for limited data disclosure or tampering if a user visits a malicious website or loads a crafted email. The attack requires user interaction to execute WebAssembly code.

Root cause

A use-after-free vulnerability exists in the WebAssembly JavaScript engine component.

Affected systems

Firefox before 158 and Thunderbird before 158.

CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Fix & remediation

Upgrade Firefox to 158 or later and Thunderbird to 158 or later. If patching must wait, disable WebAssembly via javascript.options.wasm set to false in about:config.

shell

$ sudo apt-get update && sudo apt-get install --only-upgrade firefox thunderbird

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

Ad · In-content banner

NVD description

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-109748