# CVE-2025-52536: amd64-microcode: Improper Prevention of Lock Bit Modification in SEV firmware could allow a privileged attacker to downgrade firmware...

CVE-2025-52536 is fixed in amd64-microcode on 1 platform by DEBIAN-CVE-2025-52536 (version 3.20260923.1), released February 10, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-52536
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 10, 2026

## Description

Improper Prevention of Lock Bit Modification in SEV firmware could allow a privileged attacker to downgrade firmware potentially resulting in a loss of integrity.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | amd64-microcode Debian 14 | 3.20260923.1 | [DEBIAN-CVE-2025-52536](https://patchblox.com/security/data/fix/linux/debian-cve-2025-52536.md) | Feb 10, 2026 |

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Data as of 2026-11-10T13:56:55Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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