# RHSA-2026:1236: kernel security update

RHSA-2026:1236, released December 6, 2025, fixes 7 CVEs in kernel (version 6.12.0-55.55.1.el10_0). None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2026-1236
- Platform: Linux
- Released: Dec 6, 2025
- Priority: High (Closes CVE-2025-40277, high severity)
- CVEs: 7, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2026:1236

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [kernel](https://patchblox.com/security/data/product/linux/kernel.md) | RHEL 10 | 6.12.0-55.55.1.el10_0 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-40277](https://patchblox.com/security/data/cve/CVE-2025-40277.md) | High | drm/vmwgfx: Validate command header size against SVGA_CMD_MAX_DATASIZE | 7.8 | 0.0025 |  |
| [CVE-2025-37891](https://patchblox.com/security/data/cve/CVE-2025-37891.md) | High | ALSA: ump: Fix buffer overflow at UMP SysEx message conversion | 7.8 | 0.0025 |  |
| [CVE-2025-37819](https://patchblox.com/security/data/cve/CVE-2025-37819.md) | High | irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode() | 7.8 | 0.0023 |  |
| [CVE-2025-37789](https://patchblox.com/security/data/cve/CVE-2025-37789.md) | High | net: openvswitch: fix nested key length validation in the set() action | 7.8 | 0.0022 |  |
| [CVE-2025-40154](https://patchblox.com/security/data/cve/CVE-2025-40154.md) | High | kernel: The kernel packages contain the Linux kernel, the core of any Linux operating system.  Security Fix(es):  * kernel: n... | 7.8 | 0.0021 |  |
| [CVE-2025-37761](https://patchblox.com/security/data/cve/CVE-2025-37761.md) | High | kernel: In the Linux kernel, the following vulnerability has been resolved: drm/xe: Fix an out-of-bounds shift when invalidat... | 7.1 | 0.0021 |  |
| [CVE-2025-21815](https://patchblox.com/security/data/cve/CVE-2025-21815.md) | High | kernel: In the Linux kernel, the following vulnerability has been resolved: mm/compaction: fix UBSAN shift-out-of-bounds warn... | 7.1 | 0.0019 |  |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo