Known exploited vulnerability · Linux

CVE-2021-22555: Linux Kernel Heap Out-of-Bounds Write Vulnerability

highCVSS 3.1 7.8Exploited

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/xtables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

Published Jul 7, 2021 · Updated Oct 13, 2026

Required action

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

Advisory details

From the National Vulnerability Database. This product uses the NVD API but is not endorsed or certified by the NVD.

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

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