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CVE-2021-28704

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text...

8.8 HighFix available

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.35%Down 0.1 points since Nov 24, 2021

What each source reports

NVD Score used8.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: CVE-2021-28704
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 2.0: 6.9 MediumAV:L/AC:M/Au:N/C:C/I:C/A:C
Updated: 2026-11-02

CVE ListNo score

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: CVE-2021-28704
Updated: 2026-11-02

EUVDEUVD-2021-15361No score

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: EUVD-2021-15361
Updated: 2026-11-03

GitHub AdvisoriesGHSA-gjrp-cpc9-h4r78.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text...

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: GHSA-gjrp-cpc9-h4r7
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-77
Updated: 2026-11-02

OSVALPINE-CVE-2021-287048.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: ALPINE-CVE-2021-28704
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

OSV8.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: CVE-2021-28704
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

Show 12 moreShow less

OSVDEBIAN-CVE-2021-287048.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: DEBIAN-CVE-2021-28704
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-287048.8

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

Record: UBUNTU-CVE-2021-28704
CVSS 3.1: 8.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

OSVopenSUSE-SU-2021:1543-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Update to Xen 4.13.4 bug fix release (bsc#1027519).

This update was imported from the SUSE:SLE-15-SP2:Update update project.

Record: openSUSE-SU-2021:1543-1
Updated: 2026-11-02

OSVopenSUSE-SU-2021:3968-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Update to Xen 4.14.3 bug fix release (bsc#1027519).

Record: openSUSE-SU-2021:3968-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3813-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).

Record: SUSE-SU-2021:3813-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3842-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28701: Fixed race condition in XENMAPSPACE_grant_table handling (XSA-384) (bsc#1189632).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Integrate bugfixes (bsc#1189373, bsc#1189378).

Record: SUSE-SU-2021:3842-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3849-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28701: Fixed race condition in XENMAPSPACE_grant_table handling (XSA-384) (bsc#1189632).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Integrate bugfixes (bsc#1189373, bsc#1189378)

Record: SUSE-SU-2021:3849-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3851-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).

Record: SUSE-SU-2021:3851-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3852-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Fixed 15sp4 uefi fv guest on 12sp5 host unable to bootup with sriov pci device plugin (bsc#1191510).
Upstream bug fixes (bsc#1027519).

Record: SUSE-SU-2021:3852-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3888-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Update to Xen 4.13.4 bug fix release (bsc#1027519).

Record: SUSE-SU-2021:3888-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3968-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Update to Xen 4.14.3 bug fix release (bsc#1027519).

Record: SUSE-SU-2021:3968-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3977-1No score

Security update for xen

This update for xen fixes the following issues:

CVE-2021-28701: Fixed race condition in XENMAPSPACE_grant_table handling (XSA-384) (bsc#1189632).
CVE-2021-28702: Fixed PCI devices with RMRRs not deassigned correctly (XSA-386) (bsc#1191363).
CVE-2021-28704, CVE-2021-28707, CVE-2021-28708: Fixed PoD operations on misaligned GFNs (XSA-388) (bsc#1192557).
CVE-2021-28705, CVE-2021-28709: Fixed issues with partially successful P2M updates on x86 (XSA-389) (bsc#1192559).
CVE-2021-28706: Fixed guests may exceed their designated memory limit (XSA-385) (bsc#1192554).
Upstream bug fixes (bsc#1027519)

Record: SUSE-SU-2021:3977-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`xen` Alpine:v3.11	4.7.0 up to 4.13.4-r2	4.13.4-r2
`xen` Alpine:v3.12	4.7.0 up to 4.13.4-r2	4.13.4-r2
`xen` Alpine:v3.13	4.7.0 up to 4.14.3-r2	4.14.3-r2
`xen` Alpine:v3.14	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.15	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.16	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.17	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.18	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.19	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.20	4.7.0 up to 4.15.1-r2	4.15.1-r2

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Affected packages
Package	Affected	Fixed
`xen` Alpine:v3.21	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.22	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.23	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Alpine:v3.24	4.7.0 up to 4.15.1-r2	4.15.1-r2
`xen` Debian:12	before 4.14.3+32-g9de3671772-1	4.14.3+32-g9de3671772-1
`xen` Debian:13	before 4.14.3+32-g9de3671772-1	4.14.3+32-g9de3671772-1
`xen` Debian:14	before 4.14.3+32-g9de3671772-1	4.14.3+32-g9de3671772-1
`xen` Debian:11 From an advisory covering 7 CVEs	before 4.14.3+32-g9de3671772-1~deb11u1, plus listed versions 4.14.2+25-gb6a8c4f72d-24.14.3-14.14.3-1~deb11u1	4.14.3+32-g9de3671772-1~deb11u1
`xen` SUSE:Linux Enterprise Server 12 SP2-BCL From an advisory covering 6 CVEs	before 4.7.6_18-43.82.1	4.7.6_18-43.82.1
`xen` SUSE:Linux Enterprise High Performance Computing 15-ESPOS From an advisory covering 7 CVEs	before 4.10.4_30-3.68.1	4.10.4_30-3.68.1
`xen` SUSE:Linux Enterprise High Performance Computing 15-LTSS From an advisory covering 7 CVEs	before 4.10.4_30-3.68.1	4.10.4_30-3.68.1
`xen` SUSE:Linux Enterprise Server for SAP Applications 15 From an advisory covering 7 CVEs	before 4.10.4_30-3.68.1	4.10.4_30-3.68.1
`xen` SUSE:OpenStack Cloud 9 From an advisory covering 7 CVEs	before 4.11.4_24-2.65.1	4.11.4_24-2.65.1
`xen` SUSE:OpenStack Cloud Crowbar 9 From an advisory covering 7 CVEs	before 4.11.4_24-2.65.1	4.11.4_24-2.65.1
`xen` SUSE:Linux Enterprise Server for SAP Applications 12 SP4 From an advisory covering 7 CVEs	before 4.11.4_24-2.65.1	4.11.4_24-2.65.1
`xen` SUSE:Linux Enterprise Server 12 SP4-LTSS From an advisory covering 7 CVEs	before 4.11.4_24-2.65.1	4.11.4_24-2.65.1
`xen` SUSE:HPE Helion OpenStack 8 From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:OpenStack Cloud 8 From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:OpenStack Cloud Crowbar 8 From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:Linux Enterprise Server for SAP Applications 12 SP3 From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:Linux Enterprise Server 12 SP3-LTSS From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:Linux Enterprise Server 12 SP3-BCL From an advisory covering 6 CVEs	before 4.9.4_24-3.97.1	4.9.4_24-3.97.1
`xen` SUSE:Linux Enterprise Software Development Kit 12 SP5 From an advisory covering 7 CVEs	before 4.12.4_16-3.55.1	4.12.4_16-3.55.1
`xen` SUSE:Linux Enterprise Server 12 SP5 From an advisory covering 7 CVEs	before 4.12.4_16-3.55.1	4.12.4_16-3.55.1
`xen` SUSE:Linux Enterprise Server for SAP Applications 12 SP5 From an advisory covering 7 CVEs	before 4.12.4_16-3.55.1	4.12.4_16-3.55.1
`xen` SUSE:Linux Enterprise Module for Basesystem 15 SP2 From an advisory covering 7 CVEs	before 4.13.4_02-3.40.1	4.13.4_02-3.40.1
`xen` SUSE:Linux Enterprise Module for Server Applications 15 SP2 From an advisory covering 7 CVEs	before 4.13.4_02-3.40.1	4.13.4_02-3.40.1
`xen` SUSE:Linux Enterprise Micro 5.0 From an advisory covering 7 CVEs	before 4.13.4_02-3.40.1	4.13.4_02-3.40.1
`xen` SUSE:Linux Enterprise Module for Basesystem 15 SP3 From an advisory covering 7 CVEs	before 4.14.3_04-3.15.1	4.14.3_04-3.15.1
`xen` SUSE:Linux Enterprise Module for Server Applications 15 SP3 From an advisory covering 7 CVEs	before 4.14.3_04-3.15.1	4.14.3_04-3.15.1
`xen` SUSE:Linux Enterprise Micro 5.1 From an advisory covering 7 CVEs	before 4.14.3_04-3.15.1	4.14.3_04-3.15.1
`xen` SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` SUSE:Linux Enterprise Server 15 SP1-BCL From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` SUSE:Linux Enterprise Server 15 SP1-LTSS From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` SUSE:Linux Enterprise Server for SAP Applications 15 SP1 From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` SUSE:Enterprise Storage 6 From an advisory covering 8 CVEs	before 4.12.4_16-3.57.1	4.12.4_16-3.57.1
`xen` Ubuntu:16.04:LTS	All versions, plus listed versions 4.5.1-0ubuntu14.5.1-0ubuntu24.6.0-1ubuntu14.6.0-1ubuntu24.6.0-1ubuntu4 Show 7 moreShow less 4.6.0-1ubuntu4.14.6.0-1ubuntu4.24.6.0-1ubuntu4.34.6.5-0ubuntu14.6.5-0ubuntu1.14.6.5-0ubuntu1.24.6.5-0ubuntu1.4	None known
`xen` Ubuntu:18.04:LTS	All versions, plus listed versions 4.9.0-0ubuntu34.9.0-0ubuntu44.9.2-0ubuntu1	None known
`xen` Ubuntu:20.04:LTS	All versions, plus listed versions 4.9.2-0ubuntu24.9.2-0ubuntu64.9.2-0ubuntu74.11.3+24-g14b62ab3e5-1ubuntu14.11.3+24-g14b62ab3e5-1ubuntu24.11.3+24-g14b62ab3e5-1ubuntu2.24.11.3+24-g14b62ab3e5-1ubuntu2.3	None known
`xen` Ubuntu:22.04:LTS	All versions, plus listed versions 4.11.4+24-gddaaccbbab-1ubuntu24.16.0-1~ubuntu24.16.0-1~ubuntu2.1	None known
`xen` Ubuntu:24.04:LTS	All versions, plus listed versions 4.17.2-14.17.2+55-g0b56bed864-14.17.2+76-ge1f9cb16e2-14.17.2+76-ge1f9cb16e2-1ubuntu14.17.3+10-g091466ba55-14.17.3+10-g091466ba55-1.1ubuntu24.17.3+10-g091466ba55-1.1ubuntu3	None known
`xen` Ubuntu:25.10	All versions, plus listed versions 4.20.0-1ubuntu14.20.0+68-g35cb38b222-1	None known
`xen` Ubuntu:26.10	All versions, plus listed versions 4.20.2+7-g1badcf5035-2build24.20.2+37-g61ff35323e-1ubuntu14.20.3+127-gc42374a105-1	None known
`xen` Ubuntu:26.04:LTS	All versions, plus listed versions 4.20.0+68-g35cb38b222-14.20.2+7-g1badcf5035-24.20.2+7-g1badcf5035-2build2	None known
`xen` openSUSE:Leap 15.2 From an advisory covering 7 CVEs	before 4.13.4_02-lp152.2.33.1	4.13.4_02-lp152.2.33.1
`xen` openSUSE:Leap 15.3 From an advisory covering 7 CVEs	before 4.14.3_04-3.15.1	4.14.3_04-3.15.1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-28704 is a high vulnerability (CVSS 8.8) in Xen, published November 24, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 29th percentile. Fixed in xen 4.13.4-r2.

References

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