Use after free in libvirt
Priority LOW 32CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
A use-after-free flaw was found in libvirt. The qemuMonitorUnregister() function in qemuProcessHandleMonitorEOF is called using multiple threads without being adequately protected by a monitor lock. This flaw could be triggered by the virConnectGetAllDomainStats API when the guest is shutting down. An unprivileged client with a read-only connection could use this flaw to perform a denial of service attack by causing the libvirt daemon to crash.
Why it matters now
EPSS 0.01642 76th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 4 fixed, 3 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | libvirt | Fixed in libvirt v7.1.0 | — | No fix listed | CNA |
- libvirt Vendor— Affected Fixed in libvirt v7.1.0 Fixed in — No fix listed CNA
CPE configurations NVD · 21
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:redhat:libvirt:*:*:*:*:*:*:*:* | before 7.1.0 | Vulnerable | Red Hat |
| cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:* | 21.10 | Vulnerable | Canonical |
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 35 | Vulnerable | Fedoraproject |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
- cpe:2.3:a:redhat:libvirt:*:*:*:*:*:*:*:* Versions before 7.1.0 Vulnerable ·Red Hat
- cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:* Versions 21.10 Vulnerable ·Canonical
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
Show 11 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:* | 8.6 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Running on | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* | 8.6 | Running on | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:* | 8.0 | Running on | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.6:*:*:*:*:*:*:* | 8.6 | Running on | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* | 8.0 | Running on | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:* | 8.6 | Running on | Red Hat |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
| cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Running on ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Running on ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:* Versions 8.0 Running on ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Running on ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* Versions 8.0 Running on ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Running on ·Red Hat
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
- cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
Remediation
Red Hat 1 advisory
- RHSA-2022:1759 Released 2022-05-10 · Red Hat rating Moderatevirt:rhel and virt-devel:rhel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.noarch::virt:rhel, SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.aarch64::virt:rhel +47
- Red Hat Enterprise Linux CRB (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt-devel:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel, hivex-devel-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel +47
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 Advanced Virtualization | Affected | No fix yet |
| Advanced Virtualization CodeReady Builder for RHEL 8.5.0 | Fixed | — |
| Advanced Virtualization for RHEL 8.5.0 | Fixed | — |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2022:1759 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2022:1759 |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3975
- 2026-10-03 Alias added: GHSA-pg89-46xq-98vv
References
Patch 3
Advisory 2
Sources
- CVE-2021-3975 · CVE Program
- CVE-2021-3975 · NVD
- FIRST EPSS
- GHSA-pg89-46xq-98vv · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3975 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences