Overview
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.
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
Key Details
| Property | Value |
|---|---|
| CVE ID | CVE-2021-22555 |
| Vendor / Product | Linux — Kernel |
| NVD Published | 2021-07-07 |
| NVD Last Modified | 2025-10-27 |
| CVSS 3.1 Score | 8.3 |
| CVSS 3.1 Vector | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
| Severity | HIGH |
| CWE | CWE-787 |
| CISA KEV Added | 2025-10-06 |
| CISA KEV Deadline | 2025-10-27 |
| Known Ransomware Use | No |
CVSS 3.1 Breakdown
Attack Vector
Adjacent
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Required Action
CISA BOD 22-01 Deadline: 2025-10-27.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Timeline
| Date | Event |
|---|---|
| 2025-10-06 | Added to CISA Known Exploited Vulnerabilities catalog |
| 2025-10-27 | CISA BOD 22-01 remediation deadline |
References
| Resource | Type |
|---|---|
| NVD — CVE-2021-22555 | Vulnerability Database |
| CISA KEV Catalog Entry | US Government |