Ref# ADV2026_89 | Date: Feb 17th 2026

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Mozilla published a security advisory highlighting vulnerabilities in the following products on February 16^th, 2026. It is recommended that you take the necessary precautions by ensuring your products are always updated.

• Thunderbird – versions prior to 147.0.2 and 140.7.2
• Firefox – versions prior to 147.0.4
• Firefox ESR – versions prior to 115.32.1
• Firefox ESR – versions prior to 140.7.1

For more information on these updates, you can follow this URL:

• Mozilla Foundation Security Advisory 2026-11
• Mozilla Foundation Security Advisory 2026-10
• 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 Foundation Security Advisory 2026-11. (February 16, 2026). Retrieved from Mozilla. https://www.mozilla.org/en-US/security/advisories/mfsa2026-11/

 

• Mozilla Foundation Security Advisory 2026-10. (February 16, 2026). Retrieved from Mozilla. https://www.mozilla.org/en-US/security/advisories/mfsa2026-10/

 

• Mozilla Security Advisories. (n.b.). Retrieved from Mozilla. https://www.mozilla.org/en-US/security/advisories/