Description
It was discovered that the update for the virt:rhel module in the RHSA-2020:4676 (https://access.redhat.com/errata/RHSA-2020:4676) erratum released as part of Red Hat Enterprise Linux 8.3 failed to include the fix for the qemu-kvm component issue CVE-2020-10756, which was previously corrected in virt:rhel/qemu-kvm via erratum RHSA-2020:4059 (https://access.redhat.com/errata/RHSA-2020:4059). CVE-2021-20295 was assigned to that Red Hat specific security regression. For more details about the original security issue CVE-2020-10756, refer to bug 1835986 or the CVE page: https://access.redhat.com/security/cve/CVE-2020-10756.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | QEMU | qemu-kvm 4.2.0-34 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | SLOF | 20191022-3.git899d9883.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | hivex +6 | 1.3.18-20.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | libiscsi +2 | 1.18.0-8.module+el8.1.0+4066+0f1aadab | RHSA-2021:1064 |
| RHEL 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7353+9de0a3cc | RHSA-2021:1064 |
| RHEL 8 | libvirt +28 | 6.0.0-28.1.module+el8.3.0+10448+0c705bc6 | RHSA-2021:1064 |
| RHEL 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | nbdkit +13 | 1.16.2-4.module+el8.3.0+6922+fd575af8 | RHSA-2021:1064 |
| RHEL 8 | netcf +2 | 0.2.8-12.module+el8.1.0+4066+0f1aadab | RHSA-2021:1064 |
| RHEL 8 | perl-Sys-Virt +2 | 6.0.0-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | qemu-img +10 | 15:4.2.0-34.module+el8.3.0+10437+1ca0c2ba.5 | RHSA-2021:1064 |
| RHEL 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7353+9de0a3cc | RHSA-2021:1064 |
| RHEL 8 | sgabios +1 | 1:0.20170427git-3.module+el8.1.0+4066+0f1aadab | RHSA-2021:1064 |
| RHEL 8 | supermin +1 | 5.1.19-10.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1064 |
| RHEL 8 | virt-dib +25 | 1:1.40.2-25.module+el8.3.0+7421+642fe24f | RHSA-2021:1064 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | hivex +6 | 1.3.18-20.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | libguestfs-winsupport | 8.2-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | libiscsi +2 | 1.18.0-8.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | libnbd +5 | 1.2.2-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | libvirt-dbus | 1.3.0-2.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | nbdkit +13 | 1.16.2-4.module_el8.5.0+2608+72063365 | ALSA-2021:1064 |
| AlmaLinux 8 | netcf +2 | 0.2.8-12.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | ocaml-libguestfs +1 | 1:1.40.2-25.module_el8.3.0+2048+e7a0a3ea.alma | ALSA-2021:1064 |
| AlmaLinux 8 | perl-Sys-Virt +1 | 6.0.0-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | seabios +2 | 1.13.0-2.module_el8.5.0+2608+72063365 | ALSA-2021:1064 |
| AlmaLinux 8 | sgabios | 1:0.20170427git-3.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1064 |
| AlmaLinux 8 | sgabios-bin | 1:0.20170427git-3.module_el8.5.0+2608+72063365 | ALSA-2021:1064 |
| AlmaLinux 8 | supermin +1 | 5.1.19-10.module_el8.5.0+2608+72063365 | ALSA-2021:1064 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | hivex | 1.3.18-20.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | libiscsi | 1.18.0-8.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | libnbd | 1.2.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | nbdkit | 1.16.2-4.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | netcf | 0.2.8-12.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | perl-Sys-Virt +1 | 6.0.0-1.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | seabios | 1.13.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | sgabios | 1:0.20170427git-3.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
| Rocky Linux 8 | supermin | 5.1.19-10.module+el8.4.0+534+4680a14e | RLSA-2021:1064 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | hivex +6 | 1.3.18-20.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | libiscsi +2 | 1.18.0-8.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | libvirt +28 | 6.0.0-28.1.0.1.module+el8.3.0+20008+729ca284 | ELSA-2021-1064 |
| Oracle Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | nbdkit +13 | 1.16.2-4.0.1.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | netcf +2 | 0.2.8-12.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | perl-Sys-Virt +1 | 6.0.0-1.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | qemu-img +10 | 15:4.2.0-34.module+el8.3.0+20008+729ca284.5 | ELSA-2021-1064 |
| Oracle Linux 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | sgabios +1 | 1:0.20170427git-3.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | supermin +1 | 5.1.19-10.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
| Oracle Linux 8 | virt-dib +25 | 1:1.40.2-25.0.1.module+el8.3.0+7860+a7792d29 | ELSA-2021-1064 |
Advisories 4
- ALSA-2021:1064 Moderate: virt:rhel and virt-devel:rhel security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:1064 Red Hat Security Advisory: virt:rhel and virt-devel:rhel security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- ELSA-2021-1064 Low: virt:ol and virt-devel:ol security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 16, 2026
- RLSA-2021:1064 Moderate: virt:rhel and virt-devel:rhel security update Rocky Linux Security Advisories · Feb 5, 2026