Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.
Evidence confidence: Exploitation recorded
● Hype ● Reality
Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.
First record: hype 0.0 · reality 8.2 (2026-11-02 15:12). The curve appears once the score changes.
Public exploit entries / repo candidates
Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.
Score evaluated: 2026-11-05 13:58:20.659321+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z