CVE-2026-109729

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, potentially leading to unauthorized data access or integrity compromise, if a user visits a malicious page or views malicious content. Exploitation requires user interaction to load untrusted JavaScript.

Root cause

A use-after-free condition exists in the JIT component of the JavaScript engine.

Affected systems

Firefox before 158, Firefox ESR before 115.43 and 153.5, and Thunderbird before 158 and 153.5

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 to Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, or Thunderbird 153.5. No interim mitigation is documented, so patching the affected binaries is required.

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?

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NVD description

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-109729