CVE-2021-22555Vulnerability
Linux Kernel Heap Out-of-Bounds Write Vulnerability
Exploited in the wildCISA added it to its Known Exploited Vulnerabilities list on .
Reported by 1 independent source · first reported by Kaspersky Securelist · last reported
Last reported 1 month ago
CISA KEVAdded 6 Oct 2025
Fix due 27 Oct 2025
Used by ransomware: not knownCISA KEV catalogue
Fix due 27 Oct 2025
Used by ransomware: not knownCISA KEV catalogue
EPSS78.7%
higher than 99% of CVEsFIRST EPSS, as of 22 Oct 2026
higher than 99% of CVEsFIRST EPSS, as of 22 Oct 2026
What the reports say
1 report, newest first · the exact sentence from each-
Exploits and vulnerabilities in Q2 2026“CVE-2021-22555: a heap out-of-bounds write vulnerability in the Netfilter kernel subsystem”
Indicators reported together
named in the same reportsAlso named with it: CVE-2026-43284, CVE-2025-8088, CVE-2018-0802, CVE-2017-11882, CVE-2017-0199, CVE-2023-38831, CVE-2025-6218, CVE-2026-31431, CVE-2026-43500, CVE-2026-46300, CVE-2026-31635, CVE-2026-43494, CVE-2026-46331, CVE-2022-0847, CVE-2019-13272, CVE-2023-32233, CVE-2026-35273, CVE-2023-46604, CVE-2024-12356, CVE-2026-1731
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