CVE-2021-23981: Mozilla Firefox

High severity, CVSS 8.1. EPSS: 1.1% chance of exploitation in the next 30 days.

A texture upload of a Pixel Buffer Object could have confused the WebGL code to skip binding the buffer used to unpack it, resulting in memory corruption and a potentially exploitable information leak or crash. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Affected products

• Mozilla Firefox: before 87.0 (fixed in 87.0)
• Mozilla Firefox ESR: before 78.9 (fixed in 78.9)
• Mozilla Thunderbird: before 78.9 (fixed in 78.9)

Published 2021-03-31. Last modified 2026-06-17.