CVE-2026-74978
An attacker can exploit multiple vulnerabilities in Mozilla Firefox, Firefox ESR and Thunderbird to elevate privileges, bypass security measures, disclose confidential information, perform spoofing or clickjacking attacks, or cause denial-of-service conditions.
CSIRTS triage
- What
- Multiple vulnerabilities allow attackers to elevate privileges, bypass security measures, disclose information, perform spoofing or clickjacking, or cause denial-of-service.
- Who is affected
- All users of Firefox, Firefox ESR, and Thunderbird.
- Urgency
- High severity requires prompt patching; currently not known to be exploited in the wild.
- Action
- Update to the latest patched version of Firefox, Firefox ESR, or Thunderbird.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 16% of all EPSS-scored CVEs.
Advisory coverage (4)
- high[NEW] [high] Mozilla Firefox, Firefox ESR and Thunderbird: Multiple Vulnerabilitiescert-bund · 2026-08-19
- unknownMozilla Products Multiple Vulnerabilitieshkcert · 2026-08-19
- unknownMultiple vulnerabilities in Mozilla products (August 19, 2026)cert-fr-avis · 2026-08-19
- highCVE-2026-74978: Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firef…nvd · 2026-08-18
External references
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