Home / Vulnerabilities / CVE-2021-22555
HIGH SEVERITY
CVE-2021-22555 Linux · Kernel

Linux Kernel Heap Out-of-Bounds Write Vulnerability

Technical Severity

CVSS v3.1 Metrics

HIGH
8.3 / 10
Minimal Risk Critical
Vector Specification
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Exploitation Likelihood

EPSS Prediction

85.24 %
Predictive Probability
Percentile Rank
99.3 th

Documented as more likely to be exploited than 99.3% of known CVEs.

Detection Date

Oct 06, 2025

Remediation Due

Oct 27, 2025

CISA Catalog Active

Threat Analysis

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.

Remediation Directive

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

External Intelligence

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=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d

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://security.netapp.com/advisory/ntap-20210805-0010/

https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528

https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528
NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2021-22555