How severe is CVE-2021-4091?

CVE-2021-4091 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-4091 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4091?

CVE-2021-4091 primarily affects Redhat Enterprise Linux Desktop. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-4091?

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-2021-4091 published?

CVE-2021-4091 was published on 2022-02-18 and last updated on 2026-06-17.

CVE-2021-4091

CVE-2021-4091 is a high-severity vulnerability in Redhat Enterprise Linux Desktop with a CVSS 3.x base score of 7.5. 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-415.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Redhat Enterprise Linux Desktop
Published: 2022-02-18
Last modified: 2026-06-17

Description

A double-free was found in the way 389-ds-base handles virtual attributes context in persistent searches. An attacker could send a series of search requests, forcing the server to behave unexpectedly, and crash.

Frequently asked questions

What is CVE-2021-4091?: A double-free was found in the way 389-ds-base handles virtual attributes context in persistent searches. An attacker could send a series of search requests, forcing the server to behave unexpectedly, and crash.
How severe is CVE-2021-4091?: CVE-2021-4091 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-4091 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4091?: CVE-2021-4091 primarily affects Redhat Enterprise Linux Desktop. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-4091?: 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-2021-4091 published?: CVE-2021-4091 was published on 2022-02-18 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:port389:389-ds-base:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_big_endian:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_scientific_computing:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

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CVE-2026-31609 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid double-free in…
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