Description
In the Linux kernel, the following vulnerability has been resolved:
Buffer overflow in drivers/xen/sys-hypervisor.c
The build id returned by HYPERVISOR_xen_version(XENVER_build_id) is
neither NUL terminated nor a string.
The first causes a buffer overflow as sprintf in buildid_show will
read and copy till it finds a NUL.
00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P|
00000010 b9 a8 01 42 6f 2e 32 |...Bo.2|
00000017
So use a memcpy instead of sprintf to have the correct value:
00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P|
00000010 b9 a8 01 42 |...B|
00000014
(the above have a hack to embed a zero inside and check it's
returned correctly).
This is XSA-485 / CVE-2026-31786
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.13 | 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 17 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-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-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-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | 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 | 5.14.0-687.13.1.el9_8 | RHSA-2026:24381 |
| 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 |
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 | 5.14.0-687.13.1.el9_8 | ALSA-2026:24381 |
| 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 8 | kernel | 4.18.0-553.134.1.el8_10 | RLSA-2026:26427 |
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-2026-24381 |
| Oracle Linux 8 | perf +19 | 4.18.0-553.134.1.el8_10 | ELSA-2026-26427 |
Advisories 19
- 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-2026:24381 Important: kernel security 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-2026:27288 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:24381 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 9, 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
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- ELSA-2026-24381 Important: kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 29, 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/e3af585e1728c917682b6a3de9a69b41fb9194d4
- https://git.kernel.org/stable/c/8288d031a01dbacfde3fc643f7be3d23504de64d
- https://git.kernel.org/stable/c/f458ba102da97fafca106327086fc95f3fc764cb
- https://git.kernel.org/stable/c/4b4defd2fce3f966c25adabf46644a85558f1169
- https://git.kernel.org/stable/c/5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a
- https://git.kernel.org/stable/c/d5f59216650c51e5e3fcb7517c825bc8047f60ef
- https://git.kernel.org/stable/c/52cecff98bda2c51eed1c6ce9d21c5d6268fb19d
- https://git.kernel.org/stable/c/27fdbab4221b375de54bf91919798d88520c6e28