Description
In the Linux kernel, the following vulnerability has been resolved:
xen/privcmd: fix double free via VMA splitting
privcmd_vm_ops defines .close (privcmd_close), but neither .may_split
nor .open. When userspace does a partial munmap() on a privcmd mapping,
the kernel splits the VMA via __split_vma(). Since may_split is NULL,
the split is allowed. vm_area_dup() copies vm_private_data (a pages
array allocated in alloc_empty_pages()) into the new VMA without any
fixup, because there is no .open callback.
Both VMAs now point to the same pages array. When the unmapped portion
is closed, privcmd_close() calls:
- xen_unmap_domain_gfn_range()
- xen_free_unpopulated_pages()
- kvfree(pages)
The surviving VMA still holds the dangling pointer. When it is later
destroyed, the same sequence runs again, which leads to a double free.
Fix this issue by adding a .may_split callback denying the VMA split.
This is XSA-487 / CVE-2026-31787
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 3.8 | 5.10.254 |
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 7.0.3-1 | — |
| Debian 13 | linux | 6.12.85-1 | — |
| Debian 12 | linux | 6.1.170-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1028.33 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1096.98 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-27.27 | — |
| Ubuntu 26.04 LTS | linux-aws +1 | 7.0.0-1008.8 | — |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1010.10 | — |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1007.7 | — |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1009.9 | — |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1013.13 | — |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1014.14 | — |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-27.27.1 | — |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-136.136 | — |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1061.64 | — |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1063.71 | — |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1062.69 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1064.72 | — |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1059.67 | — |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1046.50 | — |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-28.28~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1061.62 | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-136.136.2 | — |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1059.62 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1059.62.1 | — |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1030.31 | — |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1058.61 | — |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1061.65 | — |
| Ubuntu 24.04 LTS | linux-riscv +28 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1033.34 | — |
Show 19 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | linux | 5.15.0-186.196 | — |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1112.119 | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1061.64~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-azure +1 | 5.15.0-1117.126 | — |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1063.71~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1062.69~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1112.122 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1064.72~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1108.114 | — |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1095.103 | — |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-136.136~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-ibm | 5.15.0-1106.110 | — |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1061.62~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1107.113 | — |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1104.109 | — |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-184.194 | — |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-136.136.2~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1107.108 | — |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1059.62~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1064.66 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1053.53 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1109.115 | — |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1058.61~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-raspi | 5.15.0-1106.109 | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-136.136~22.04.3 | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1075.79 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2050.52 | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1056.57 | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1104.106 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1111.120 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1056.57~22.04.2 | — |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1061.64+fips1 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1063.71+fips2 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-136.136+fips2 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1064.72+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1112.119+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1117.126+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-186.196+fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1112.122+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +10 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1112.119~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1117.126~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1117.126~20.04.2 | — |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1112.122~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-186.196~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 +1 | 5.15.0-1106.110~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1107.113~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-184.194~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1064.66~20.04.1 | — |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1109.115~20.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +76 | 6.12.0-211.26.1.el10_2 | RHSA-2026:27288 |
| RHEL 9 | rv +75 | 5.14.0-687.17.1.el9_8 | RHSA-2026:27789 |
| RHEL 8 | kernel-rt +12 | 4.18.0-553.134.1.rt7.475.el8_10 | RHSA-2026:26428 |
| RHEL 8 | perf +26 | 4.18.0-553.134.1.el8_10 | RHSA-2026:26427 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | rv +77 | 6.12.0-55.95.1.el10_0 | RHSA-2026:52764 |
| RHEL 9.4 E4S | bpftool | 7.3.0-427.141.1.el9_4 | RHSA-2026:48386 |
| RHEL 9.4 E4S | rv +62 | 5.14.0-427.141.1.el9_4 | RHSA-2026:48386 |
| RHEL 9.2 E4S | bpftool | 7.0.0-284.186.1.el9_2 | RHSA-2026:51603 |
| RHEL 9.2 E4S | kernel-rt +14 | 5.14.0-284.186.1.rt14.471.el9_2 | RHSA-2026:51604 |
| RHEL 9.2 E4S | perf +47 | 5.14.0-284.186.1.el9_2 | RHSA-2026:51603 |
| RHEL 8.8 TUS | perf +17 | 4.18.0-477.158.1.el8_8 | RHSA-2026:52649 |
| RHEL 8.8 E4S | perf +18 | 4.18.0-477.158.1.el8_8 | RHSA-2026:52649 |
| RHEL 8.6 EUS Long Life | perf +17 | 4.18.0-372.206.1.el8_6 | RHSA-2026:53989 |
| RHEL 8.6 AUS | perf +17 | 4.18.0-372.206.1.el8_6 | RHSA-2026:53989 |
| RHEL 8.4 EUS Long Life | perf +17 | 4.18.0-305.200.1.el8_4 | RHSA-2026:47248 |
| RHEL 8.4 AUS | perf +17 | 4.18.0-305.200.1.el8_4 | RHSA-2026:47248 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | rv +74 | 6.12.0-211.26.1.el10_2 | ALSA-2026:27288 |
| AlmaLinux 9 | rv +73 | 5.14.0-687.17.1.el9_8 | ALSA-2026:27789 |
| AlmaLinux 8 | kernel-rt +9 | 4.18.0-553.134.1.rt7.475.el8_10 | ALSA-2026:26428 |
| AlmaLinux 8 | perf +24 | 4.18.0-553.134.1.el8_10 | ALSA-2026:26427 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | kernel | 6.12.0-211.26.1.el10_2 | RLSA-2026:27288 |
| Rocky Linux 9 | kernel | 5.14.0-687.17.1.el9_8 | RLSA-2026:27789 |
| Rocky Linux 8 | kernel | 4.18.0-553.134.1.el8_10 | RLSA-2026:26427 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.55.1 | SUSE-SU-2026:2238-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.55.1.150700.17.33.1 | SUSE-SU-2026:2238-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.112.1 | SUSE-SU-2026:2195-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.112.1.150600.12.52.1 | SUSE-SU-2026:2195-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | kernel-default-base | 6.4.0-150600.23.112.1.150600.12.52.1 | SUSE-SU-2026:2195-1 |
| SLES for SAP 15 SP6 | kernel-docs +4 | 6.4.0-150600.23.112.1 | SUSE-SU-2026:2195-1 |
| SLE Micro 6.2 | kernel-syms +1 | 6.12.0-160000.33.1 | SUSE-SU-2026:21834-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.55.1 | SUSE-SU-2026:2238-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_15 | 1-150700.15.3.1 | SUSE-SU-2026:2238-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.112.1 | SUSE-SU-2026:2195-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_26 | 1-150600.13.3.1 | SUSE-SU-2026:2195-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 7.0.3-1.1 | openSUSE-SU-2026:10703-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.30-61.116 +2 | 1:1.0-0.amzn2023 | ALAS2023-2026-1816, ALAS2023-2026-1754, ALAS2023-2026-1694 |
| Amazon Linux 2023 | perf +11 | 1:6.1.170-210.320.amzn2023 | ALAS2023-2026-1694 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.90-120.164.amzn2023 | ALAS2023-2026-1816 |
| Amazon Linux 2023 | perf6.18 +11 | 1:6.18.30-61.116.amzn2023 | ALAS2023-2026-1754 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | rv +29 | 6.12.0-211.34.1.el10_2 | ELSA-2026-27288 |
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-204.92.4.2.el10uek | ELSA-2026-50372 |
| Oracle Linux 9 | rv +28 | 5.14.0-687.17.1.el9_8 | ELSA-2026-27789 |
| Oracle Linux 8 | perf +19 | 4.18.0-553.134.1.el8_10 | ELSA-2026-26427 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
0xAtharv/CVE-2026-31787 ★ 0 · Sep 4, 2026
Linux kernel double free in Xen privcmd driver
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 30
- RHSA-2026:53989 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:48386 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:51603 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:51604 Red Hat Security Advisory: kernel-rt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:26427 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:26428 Red Hat Security Advisory: kernel-rt security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- ALSA-2026:27789 Important: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:27288 Important: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:26427 Important: kernel security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:26428 Important: kernel-rt security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:27789 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:27288 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:52764 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:52649 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:47248 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- WID-SEC-2026-1306 Xen und Citrix Systems XenServer: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 4, 2026
- ALAS2023-2026-1816 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 5, 2026
- ELSA-2026-27288 Important: kernel security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Aug 5, 2026
- ALAS2023-2026-1754 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 29, 2026
- SUSE-SU-2026:21834-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- SUSE-SU-2026:2238-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 1, 2026
- SUSE-SU-2026:2195-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 1, 2026
- RLSA-2026:27789 Important: kernel security, bug fix, and enhancement update Rocky Linux Security Advisories · Jun 25, 2026
- ELSA-2026-27789 Important: kernel security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 23, 2026
- RLSA-2026:27288 Important: kernel security, bug fix, and enhancement update Rocky Linux Security Advisories · Jun 22, 2026
- RLSA-2026:26427 Important: kernel security update Rocky Linux Security Advisories · Jun 19, 2026
- ELSA-2026-26427 Important: kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jun 17, 2026
- ALAS2023-2026-1694 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 13, 2026
- openSUSE-SU-2026:10703-1 kernel-devel-7.0.3-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2026
References
- https://git.kernel.org/stable/c/dbf862ce9f009128ab86b234d91413a3e450beb4
- https://git.kernel.org/stable/c/2b985d3a024b9e8c24e21671b34e855569763808
- https://git.kernel.org/stable/c/1576ff3869cbd3620717195f971c85b7d7fd62b5
- https://git.kernel.org/stable/c/402d84ad9e89bd4cbfd07ca8598532b7021daf95
- https://git.kernel.org/stable/c/2894a351fe2ea8684919d36df3188b9a35e3926f
- https://git.kernel.org/stable/c/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0
- https://git.kernel.org/stable/c/71bf829800758a6e3889096e4754ef47ba7fc850
- https://git.kernel.org/stable/c/24daca4fc07f3ff8cd0e3f629cd982187f48436a