CVE-2026-109780

—Unscored

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

—Unscored

Attack vector: —
Complexity: —
Privileges needed: —
User interaction: —
Impact: —
Weakness: —

Impact

Attackers can bypass security mitigations via web content if a user views a malicious page or email. They need the target to load untrusted HTML or DOM content in a vulnerable browser or email client.

Root cause

A mitigation bypass flaw exists within the DOM: Core & HTML component.

Affected systems

Firefox versions prior to 158 and Thunderbird versions prior to 158.

Fix & remediation

Upgrade Firefox to version 158 or later and Thunderbird to version 158 or later. No interim mitigation is provided, so prioritize patching immediately.

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

Mitigation bypass in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-109780