Ref# ADV2026_17 | Date: Jan 15th 2026

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Mozilla published a security advisory highlighting vulnerabilities in the following products on January 13, 2026. It is recommended that you take the necessary precautions by ensuring your products are always updated. 

• Firefox ESR – versions prior to 140.7 

• Firefox ESR – versions prior to 115.32 

• Firefox – versions prior to 147 

For more information on these updates, you can follow these URLs: 

• Mozilla Foundation Security Advisory 2026-03 

• Mozilla Foundation Security Advisory 2026-02 

• Mozilla Foundation Security Advisory 2026-01 

• Mozilla Security Advisories 

The Guyana National CIRT recommends that users and administrators review these updates and apply them where necessary. 

PDF Download: Mozilla Security Advisory

References 

• Mozilla Security Advisory (January 13th, 2026). Retrieved from Mozilla. https://www.mozilla.org/en-US/security/advisories/mfsa2026-03/ 

• Mozilla Security Advisory. (January 14th, 2026). Retrieved from Canadian Centre for Cyber Security. https://www.cyber.gc.ca/en/alerts-advisories/mozilla-security-advisory-av26-028