CVE-2026-109736

8.1High

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

8.1High

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Impact: High impact on confidentiality, integrity
Weakness: CWE-451

Impact

Remote attackers can spoof or manipulate user interface contents with high confidentiality and integrity impact if a user visits a malicious page or views a malicious email. It requires user interaction to trigger.

Root cause

A frame poisoning flaw exists in the Layout engine's user interface rendering logic.

Affected systems

Firefox versions prior to 158, Firefox ESR versions prior to 153.5, Thunderbird versions prior to 158, and Thunderbird ESR versions prior to 153.5.

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

Fix & remediation

Upgrade to Firefox 158, Firefox ESR 153.5, Thunderbird 158, or Thunderbird 153.5. No interim mitigations or configuration workarounds are provided.

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

Frame poisoning in the Layout component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-109736