Description
This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.11.15. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs prior to executing them. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-13661.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Kernel | 5.11.15 | — |
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 | 5.10.38-1 | — |
| Debian 13 | linux | 5.10.38-1 | — |
| Debian 12 | linux | 5.10.38-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-aws-5.8 | 5.8.0-1038.40~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-azure-5.8 | 5.8.0-1036.38~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-gcp-5.8 | 5.8.0-1035.37~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.8 | 5.8.0-59.66~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-oem-5.10 | 5.10.0-1032.33 | USN-5001-1 |
| Ubuntu 20.04 LTS | linux-oracle-5.8 | 5.8.0-1033.34~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-riscv +1 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv-5.8 | 5.8.0-29.31~20.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | kernel-rt +12 | 4.18.0-348.rt7.130.el8 | RHSA-2021:4140 |
| RHEL 8 | perf +26 | 4.18.0-348.el8 | RHSA-2021:4356 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | kernel-tools-libs-devel | 4.18.0-348.el8 | ALSA-2021:4356 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 15 SP3 | kernel-livepatch-SLE15-SP3_Update_0 | 7-3.1 | SUSE-SU-2021:3360-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | perf +19 | 4.18.0-348.el8 | ELSA-2021-4356 |
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.
GitHub 1 repository
-
WhatsWrongAndWhy/CVE-2021-31440 ★ 0 · Jul 21, 2026
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 8
- ALSA-2021:4356 Moderate: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:4356 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2021:4140 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 14, 2026
- USN-4999-1 linux, linux-aws, linux-aws-5.8, linux-azure, linux-azure-5.8, linux-gcp, linux-gcp-5.8, linux-hwe-5.8, linux-kvm, linux-oracle, linux-oracle-5.8, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5001-1 linux-oem-5.10 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- SUSE-SU-2021:3360-1 Security update for the Linux Kernel (Live Patch 0 for SLE 15 SP3) SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2022-0137 Android Patchday Juni 2022 BSI CERT-Bund (WID) · Jun 24, 2024
- ELSA-2021-4356 Moderate: kernel security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 16, 2021