Mozilla Products Multiple Vulnerabilities

CSIRTS triage

What

Multiple vulnerabilities affect Mozilla products including Firefox and derivatives.

Who is affected

Users of Mozilla Firefox and related products are affected.

Urgency

Multiple CVEs present; assess severity via CVE details before deploying patches.

Action

Update Mozilla products to the latest patched versions.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

HKCERT Security Bulletins (HK · national-cert · site)

Severity

unknown

Published

2026-09-02

Exploitation

Not in CISA KEV at last sync

Original advisory: https://www.hkcert.org/security-bulletin/mozilla-products-multiple-vulnerabilities_20260902

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-163650.27% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 19% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-163710.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-749520.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-758740.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-812670.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all EPSS-scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• high[NEW] [high] Mozilla Firefox and Thunderbird: Multiple Vulnerabilitiescert-bund
• high[NEW] [high] Mozilla Firefox, Firefox ESR and Thunderbird: Multiple Vulnerabilitiescert-bund
• high[NEW] [high] Mozilla Firefox and Firefox ESR: Multiple vulnerabilitiescert-bund
• unknownDSA-6481-1 firefox-esr - security updatedebian
• unknownMultiple vulnerabilities in Mozilla products (02 September 2026)cert-fr-avis
• highCVE-2026-84642: The values of the mail.allowed_attachment_hostnames advanced config setting were used in a reg…nvd
• highCVE-2026-84641: A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a cra…nvd
• highCVE-2026-84640: A maliciously constructed mail header could lead to a one byte read past the end of a buffer. …nvd
• criticalCVE-2026-84639: Triggering an error condition in certain MIME bodies would cause uninitialized memory to be us…nvd
• criticalCVE-2026-84637: Malicious calendar invitations could use file URI attachments to launch local or network-hoste…nvd
• highCVE-2026-84145: Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 14…nvd
• unknownCVE-2026-84144: Internally found bugs present in Thunderbird 154 and Thunderbird ESR 153.1. Some of these bugs…nvd

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