# RHSA-2021:4088: Security update for 12 packages

RHSA-2021:4088, released November 2, 2021, fixes 3 CVEs across 12 products. None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2021-4088
- Platform: Linux
- Released: Nov 2, 2021
- Priority: High (Closes CVE-2020-36385, high severity)
- CVEs: 3, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2021:4088

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [kernel-rt](https://patchblox.com/security/data/product/linux/kernel-rt.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-core](https://patchblox.com/security/data/product/linux/kernel-rt-core.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug](https://patchblox.com/security/data/product/linux/kernel-rt-debug.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug-core](https://patchblox.com/security/data/product/linux/kernel-rt-debug-core.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug-devel](https://patchblox.com/security/data/product/linux/kernel-rt-debug-devel.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug-kvm](https://patchblox.com/security/data/product/linux/kernel-rt-debug-kvm.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug-modules](https://patchblox.com/security/data/product/linux/kernel-rt-debug-modules.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-debug-modules-extra](https://patchblox.com/security/data/product/linux/kernel-rt-debug-modules-extra.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-devel](https://patchblox.com/security/data/product/linux/kernel-rt-devel.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-kvm](https://patchblox.com/security/data/product/linux/kernel-rt-kvm.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-modules](https://patchblox.com/security/data/product/linux/kernel-rt-modules.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |
| [kernel-rt-modules-extra](https://patchblox.com/security/data/product/linux/kernel-rt-modules-extra.md) | RHEL 8 | 0:4.18.0-305.25.1.rt7.97.el8_4 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2020-36385](https://patchblox.com/security/data/cve/CVE-2020-36385.md) | High | bpftool: The kernel packages contain the Linux kernel, the core of any Linux operating system.  Security Fix(es):  * kernel: u... | 7.8 | 0.0148 |  |
| [CVE-2021-3656](https://patchblox.com/security/data/cve/CVE-2021-3656.md) | High | bpftool: The kernel packages contain the Linux kernel, the core of any Linux operating system.  Security Fix(es):  * kernel: u... | 8.8 | 0.0066 |  |
| [CVE-2021-0512](https://patchblox.com/security/data/cve/CVE-2021-0512.md) | High | kpatch-patch-4_18_0-305_19_1: This is a kernel live patch module which is automatically loaded by the RPM post-install script to modify the code of... | 7.8 | 0.0028 |  |

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Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo