How severe is CVE-2021-4154?

CVE-2021-4154 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-4154 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4154?

CVE-2021-4154 primarily affects Redhat Virtualization. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-4154?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-4154 published?

CVE-2021-4154 was published on 2022-02-04 and last updated on 2026-06-17.

CVE-2021-4154

CVE-2021-4154 is a high-severity vulnerability in Redhat Virtualization with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.2
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Redhat Virtualization
Published: 2022-02-04
Last modified: 2026-06-17

Description

A use-after-free flaw was found in cgroup1_parse_param in kernel/cgroup/cgroup-v1.c in the Linux kernel's cgroup v1 parser. A local attacker with a user privilege could cause a privilege escalation by exploiting the fsconfig syscall parameter leading to a container breakout and a denial of service on the system.

Frequently asked questions

What is CVE-2021-4154?: A use-after-free flaw was found in cgroup1_parse_param in kernel/cgroup/cgroup-v1.c in the Linux kernel's cgroup v1 parser. A local attacker with a user privilege could cause a privilege escalation by exploiting the fsconfig syscall parameter leading to a container breakout and a denial of service on the system.
How severe is CVE-2021-4154?: CVE-2021-4154 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-4154 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4154?: CVE-2021-4154 primarily affects Redhat Virtualization. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-4154?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-4154 published?: CVE-2021-4154 was published on 2022-02-04 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:*
cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h300e:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h300s:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h410s:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h500e:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h500s:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h700e:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_baseboard_management_controller:h700s:*:*:*:*:*:*:*

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CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
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