CVE-2026-63824

Local privilege escalation via undersized asymmetric buffer

Published Jul 19, 2026 · Updated Jul 19, 2026

Heap buffer overflow in the Linux Kernel KEYS subsystem allows local users to escalate privileges through keyctl operations. The keyctl_pkey_params_get_2() path allocates its internal output buffer from caller-controlled out_len, although asymmetric operations can write the cryptographic primitive maximum. Local users with KEY_NEED_SEARCH on an asymmetric key can corrupt or read adjacent kernel heap memory and crash the kernel.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in the Linux Kernel KEYS subsystem allows local users to escalate privileges through keyctl operations. The keyctl_pkey_params_get_2() path allocates its internal output buffer from caller-controlled out_len, although asymmetric operations can write the cryptographic primitive maximum. Local users with KEY_NEED_SEARCH on an asymmetric key can corrupt or read adjacent kernel heap memory and crash the kernel.

The record

CVE
CVE-2026-63824
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=00d60fd3b93219ea854220f0fd264b86398cbc53 <0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3
  2. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <5165f1cc727f1322456735df212d8e26ec237a8d
  3. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <5966e4e2ba213ab7ad559166152eb4f1f170dd2c
  4. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <622ec2dcd59f21623f2a7ab773c80ceb7d555e3a
  5. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <670fc6a311ed321522b7fff92cf0fc376b4f6e78
  6. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <b11c1fa32667692a2c0566e10163758e786e430c
  7. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <b1e247338bc71826a2d2def3e0874c34749df69a
  8. Affected versionversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b
  9. Affected versionversion=4.20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=00d60fd3b93219ea854220f0fd264b86398cbc53 <0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <5165f1cc727f1322456735df212d8e26ec237a8d; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <5966e4e2ba213ab7ad559166152eb4f1f170dd2c; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <622ec2dcd59f21623f2a7ab773c80ceb7d555e3a; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <670fc6a311ed321522b7fff92cf0fc376b4f6e78; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <b11c1fa32667692a2c0566e10163758e786e430c; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <b1e247338bc71826a2d2def3e0874c34749df69a; version=00d60fd3b93219ea854220f0fd264b86398cbc53 <cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b; version=4.20

Published CVSS scores

7.8Linux kernel CNACVSS: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.

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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