Is It On KEV?

Linux Kernel

YES - ON THE CISA KEV LIST
CVE-2021-22555

Linux Kernel Heap Out-of-Bounds Write Vulnerability

CISA catalog due date2025-10-27
overdue since 2025-10-27
EPSS exploit probability (next 30 days)78.7% · 100percentile
From CVE publication to KEV listing1552 days (2021-07-07 → 2025-10-06)
Remediation window (KEV listing to due date)21 days
Days on the KEV list401 days
Date added to KEV2025-10-06
Known ransomware campaign useUnknown
VendorLinux
ProductKernel
Weaknesses (CWE)CWE-787

Linux: 32 entries (1.8% of all KEV entries are from this vendor); 9 added in 2026.

BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.

Your BOD 26-04 window (SSVC tier helper)

Your remediation window ends:

Description

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.

Required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Notes

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21 ; https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d ; https://security.netapp.com/advisory/ntap-20210805-0010/ ; https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528 ; https://nvd.nist.gov/vuln/detail/CVE-2021-22555

References

Other KEV entries for this vendor: Linux

Linux - Vendors with KEV entries

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