CVE-2023-53536

Local kernel compromise via retained freed key

Published Oct 4, 2025 · Updated Oct 4, 2025

Use-after-free in the Linux kernel blk-crypto subsystem allows local users to compromise the kernel through failed key eviction. blk_crypto_evict_key() returns without unlinking an in-use or unevictable key, but its caller frees the key before blk_crypto_reprogram_all_keys() dereferences the stale entry. Reachability requires local access to an fscrypt-encrypted volume using inline crypto; exploitation exposes or corrupts data, gains kernel control, or crashes the system.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel blk-crypto subsystem allows local users to compromise the kernel through failed key eviction. blk_crypto_evict_key() returns without unlinking an in-use or unevictable key, but its caller frees the key before blk_crypto_reprogram_all_keys() dereferences the stale entry. Reachability requires local access to an fscrypt-encrypted volume using inline crypto; exploitation exposes or corrupts data, gains kernel control, or crashes the system.

The record

CVE
CVE-2023-53536
Published
Oct 4, 2025
Updated
Oct 4, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <5bb4005fb667c6e2188fa87950f8d5faf2994410
  2. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <5c62852942667c613de0458fc797c5b8c36112b5
  3. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <5c7cb94452901a93e90c2230632e2c12a681bc92
  4. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <64ef787bb1588475163069c2e62fdd8f6c27b1f6
  5. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <701a8220762ff90615dc91d3543f789391b63298
  6. Affected versionversion=1b2628397058ebce7277480960b29c788138de90 <809a5be62e92a444a3c3d7b9f438019d0b322f55
  7. Affected versionversion=5.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1b2628397058ebce7277480960b29c788138de90 <5bb4005fb667c6e2188fa87950f8d5faf2994410; version=1b2628397058ebce7277480960b29c788138de90 <5c62852942667c613de0458fc797c5b8c36112b5; version=1b2628397058ebce7277480960b29c788138de90 <5c7cb94452901a93e90c2230632e2c12a681bc92; version=1b2628397058ebce7277480960b29c788138de90 <64ef787bb1588475163069c2e62fdd8f6c27b1f6; version=1b2628397058ebce7277480960b29c788138de90 <701a8220762ff90615dc91d3543f789391b63298; version=1b2628397058ebce7277480960b29c788138de90 <809a5be62e92a444a3c3d7b9f438019d0b322f55; version=5.8

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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