CVE-2026-74977

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 154 Firefox ESR versions prior to 153.1 Thunderbird versions prior to 154 Thunderbird versions prior to 153.1

Description An integer overflow occurs within the Graphics component. An integer overflow is a condition where an arithmetic operation attempts to create a numeric value that is outside of the range that can be represented with a given number of bits.

Recommendations Update Firefox to version 154. Update Firefox ESR to version 153.1. Update Thunderbird to version 154. Update Thunderbird to version 153.1.