CVE-2026-44983: Servo Smallbitvec

High severity, CVSS 7.3. EPSS: 0.2% chance of exploitation in the next 30 days.

smallbitvec is a growable bit-vector for Rust, optimized for size. From 1.0.1 to 2.6.0, an integer overflow in the internal capacity calculation of smallbitvec can lead to an undersized heap allocation, resulting in a heap buffer overflow through safe APIs only. This allows memory corruption without requiring unsafe code from the caller. This vulnerability is fixed in 2.6.1.

Affected products

• Servo Smallbitvec: from 1.0.1, before 2.6.1 (fixed in 2.6.1)

Published 2026-05-26. Last modified 2026-07-24.