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Unscored Public exploit CVE-2021-26708 EUVD-2021-13497GHSA-hhxw-8c9w-q5q9

A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are…

Published Feb 5, 2021 · Updated Aug 3, 2024 · Assigned by mitre

Package: linux Package: linux-aws-5.0 Package: linux-aws-5.3 Package: linux-azure Package: linux-azure-5.3 Package: linux-azure-edge Package: linux-gcp Package: linux-gcp-5.3 Package: linux-gcp-edge Package: linux-hwe Package: linux-hwe-5.8 Package: linux-hwe-edge Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.6 Package: linux-oracle-5.0 Package: linux-oracle-5.3 Package: linux-raspi2 Package: linux-riscv Package: linux-riscv-5.8 Ecosystem: Debian Ecosystem: Ubuntu

Description

A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

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 ↗
ReleasePackageFixed inAdvisory
Debian 14 linux 5.10.13-1 —
Debian 13 linux 5.10.13-1 —
Debian 12 linux 5.10.13-1 —

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-hwe-5.8 5.8.0-43.49~20.04.1 USN-4727-1
Ubuntu 20.04 LTS linux-oem-5.10 5.10.0-1016.17 —
Ubuntu 20.04 LTS linux-oem-5.6 5.6.0-1047.51 USN-4727-1
Ubuntu 20.04 LTS linux-riscv +1 No fix yet —
Ubuntu 20.04 LTS linux-riscv-5.8 5.8.0-16.18~20.04.1 —
Ubuntu 18.04 LTS linux-gcp +12 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —

Red Hat

Security tracker ↗
ReleasePackageFixed inAdvisory
RHEL 8 kernel-rt +12 4.18.0-240.22.1.rt7.77.el8_3 RHSA-2021:1081
RHEL 8 perf +26 4.18.0-240.22.1.el8_3 RHSA-2021:1093

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 8 kernel-abi-whitelists +1 4.18.0-240.22.1.el8_3 ALSA-2021:1093

openSUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed kernel-source 5.14.6-1.4 openSUSE-SU-2024:13704-1, openSUSE-SU-2024:10728-1

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 8 perf +19 4.18.0-240.22.1.el8_3 ELSA-2021-1093

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 3 repositories

  • jordan9001/vsock_poc ★ 28 · Feb 15, 2021

    Investigating the bug behind CVE-2021-26708

  • kungaocode/vulnerability-analysis- ★ 1 · Aug 7, 2026

    Automated reproduction and analysis of CVE-2021-26708 — a use-after-free vulnerability in the Linux kernel's AF_VSOCK subsystem (v5.10.12). Includes PoC exploit code, KASAN runtime detection report, …

  • azpema/CVE-2021-26708 ★ 0 · Mar 15, 2021

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 7

References