ACTIVELY EXPLOITED
CVE-2021-22555: Linux Kernel Heap Out-of-Bounds Write Vulnerability
| Vendor | Linux |
|---|---|
| Product | Kernel |
| Actively exploited | Yes |
| Added to CISA KEV | 6 Oct 2025 |
| CISA federal deadline | 27 Oct 2025 |
| Weakness (CWE) | CWE-787 |
Required action (CISA's text)
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description (NVD)
Linux Kernel contains a heap out-of-bounds write vulnerability that could allow an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space.
SOURCES
Other Linux flaws
- CVE-2026-46300: Linux Kernel Missing Initialization of a Variable Vulnerability
- CVE-2026-53266: Linux Kernel Out-of-Bounds Write Vulnerability
- CVE-2025-39964: Linux Kernel Race Condition Vulnerability
- CVE-2025-39682: Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
- CVE-2026-53362: Linux Kernel Unspecified Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.