CVE-2021-21781: Linux Kernel

Low severity, CVSS 3.3. EPSS: 0.5% chance of exploitation in the next 30 days.

An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11

Affected products

• Linux Linux Kernel: version 5.4.54 only; version 5.4.66 only
• Oracle Communications Cloud Native Core Binding Support Function: version 22.1.3 only
• Oracle Communications Cloud Native Core Network Exposure Function: version 22.1.1 only
• Oracle Communications Cloud Native Core Policy: version 22.2.0 only

Published 2021-08-18. Last modified 2026-06-17.