Cyber watch · 11/05/2026

Multiple vulnerabilities in Mozilla products

Multiple vulnerabilities have been discovered in Mozilla products. Summary of immediate actions for affected organizations.

Multiple vulnerabilities have been discovered in Mozilla products. These vulnerabilities allow an attacker to execute arbitrary code and create a security issue not specified by the vendor.

Risks

  • Arbitrary code execution
  • Unspecified by the vendor

Affected systems

  • Firefox ESR versions prior to 115.35.2
  • Firefox ESR versions prior to 140.10.2
  • Firefox versions prior to 150.0.2
  • Thunderbird ESR versions prior to 140.10.2
  • Thunderbird versions prior to 140.10.2
  • Thunderbird versions prior to 150.0.2

Immediate recommendations

Refer to the publisher’s security bulletin to obtain fixes (see Documentation section on this page of the CERT-FR website: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-0555/)