CVE-2026-109780

criticalpriority · track · 0EPSS 0.004 · 30 %ileDEFR

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.36% (30th) EPSS

CVSS 9.8 · critical

Is it mine?

10 products

Who says so?

2 sources

cert_bund · certfr

EPSS · scored 2026-10-27

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

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.1–9.8

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 3.9 · impact 5.9

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17.1highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Lsecondary · grimoire (LLM-derived)LLM-inferred

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

The CWE weakness classes this flaw belongs to.

Products and version ranges known to be affected.

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3942Mozilla Firefox und Thunderbrid: Mehrere SchwachstellenDeutsch2026-10-13csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mozilla Firefox und Mozilla Thunderbrid ausnutzen, um seine Privilegien zu erhöhen, Sicherheitsmaßnahmen zu umgehen, Spoofing-Angriffe durchzuführen, Daten offenzulegen oder zu manipulieren, Denial-of-Service-Zustände zu verursachen oder andere, nicht näher spezifizierte Angriffe durchzuführen.
CERTFR-2026-AVI-1305Multiples vulnérabilités dans les produits MozillaFrançais2026-10-14vendor · certfrFR

Which sources assert this record, and when.

published 2026-10-13modified 2026-10-26

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.