CVE-2026-74566

Key-description collisions via mismatched keyring index calculations

Published Aug 15, 2026 · Updated Aug 15, 2026

Keyring indexing flaw in Linux kernel branches beginning with 5.3 allows local users to create collisions with crafted key descriptions. keyring_get_key_chunk() loads description bytes in the opposite order from keyring_diff_objects(), which also folds an absolute byte index into a level that already includes the inline-prefix offset. Low-privileged local access is required; published sources do not specify whether resulting collisions cause a hang, crash, or another service failure.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Keyring indexing flaw in Linux kernel branches beginning with 5.3 allows local users to create collisions with crafted key descriptions. keyring_get_key_chunk() loads description bytes in the opposite order from keyring_diff_objects(), which also folds an absolute byte index into a level that already includes the inline-prefix offset. Low-privileged local access is required; published sources do not specify whether resulting collisions cause a hang, crash, or another service failure.

The record

CVE
CVE-2026-74566
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record 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=5.3
  2. Affected versionversion=f771fde82051976a6fc0fd570f8b86de4a92124b <3d9f16c0b643ceac305526b2e2fe25c2c6166926
  3. Affected versionversion=f771fde82051976a6fc0fd570f8b86de4a92124b <58565eef0f8d861aae92abfb7658458d661cee17
  4. Affected versionversion=f771fde82051976a6fc0fd570f8b86de4a92124b <7269df3e7fcfa308e6a456305162f7788747bdbd
  5. Affected versionversion=f771fde82051976a6fc0fd570f8b86de4a92124b <7e5397a3fed0dee7779bd084bec3c0584db3c930
  6. Affected versionversion=f771fde82051976a6fc0fd570f8b86de4a92124b <bd0f976ef89dce6db458bf75bc2cf51127becc41

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.3; version=f771fde82051976a6fc0fd570f8b86de4a92124b <3d9f16c0b643ceac305526b2e2fe25c2c6166926; version=f771fde82051976a6fc0fd570f8b86de4a92124b <58565eef0f8d861aae92abfb7658458d661cee17; version=f771fde82051976a6fc0fd570f8b86de4a92124b <7269df3e7fcfa308e6a456305162f7788747bdbd; version=f771fde82051976a6fc0fd570f8b86de4a92124b <7e5397a3fed0dee7779bd084bec3c0584db3c930; version=f771fde82051976a6fc0fd570f8b86de4a92124b <bd0f976ef89dce6db458bf75bc2cf51127becc41

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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