CVE-2024-26737

Kernel crash via racing BPF timer cancellation

Published Apr 3, 2024 · Updated Aug 5, 2026

Use-after-free in Linux kernel BPF timer helpers from 5.15 allows local users with BPF privileges to crash the kernel through a timer race. The bpf_timer_cancel helper dereferences a bpf_hrtimer after concurrent bpf_timer_cancel_and_free has removed and freed it outside the spin lock. Reaching the race requires local low-privileged BPF capability, and successful triggering can interrupt the host by crashing its kernel.

CVSS severity7.8
High
EPSS probability0.25%
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 Linux kernel BPF timer helpers from 5.15 allows local users with BPF privileges to crash the kernel through a timer race. The bpf_timer_cancel helper dereferences a bpf_hrtimer after concurrent bpf_timer_cancel_and_free has removed and freed it outside the spin lock. Reaching the race requires local low-privileged BPF capability, and successful triggering can interrupt the host by crashing its kernel.

The record

CVE
CVE-2024-26737
Published
Apr 3, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.15
  2. Affected versionversion=b00628b1c7d595ae5b544e059c27b1f5828314b4 <0281b919e175bb9c3128bd3872ac2903e9436e3f
  3. Affected versionversion=b00628b1c7d595ae5b544e059c27b1f5828314b4 <5268bb02107b9eedfdcd51db75b407d10043368c
  4. Affected versionversion=b00628b1c7d595ae5b544e059c27b1f5828314b4 <7d80a9e745fa5b47da3bca001f186c02485c7c33
  5. Affected versionversion=b00628b1c7d595ae5b544e059c27b1f5828314b4 <8327ed12e8ebc5436bfaa1786c49988894f9c8a6
  6. Affected versionversion=b00628b1c7d595ae5b544e059c27b1f5828314b4 <addf5e297e6cbf5341f9c07720693ca9ba0057b5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=b00628b1c7d595ae5b544e059c27b1f5828314b4 <0281b919e175bb9c3128bd3872ac2903e9436e3f; version=b00628b1c7d595ae5b544e059c27b1f5828314b4 <5268bb02107b9eedfdcd51db75b407d10043368c; version=b00628b1c7d595ae5b544e059c27b1f5828314b4 <7d80a9e745fa5b47da3bca001f186c02485c7c33; version=b00628b1c7d595ae5b544e059c27b1f5828314b4 <8327ed12e8ebc5436bfaa1786c49988894f9c8a6; version=b00628b1c7d595ae5b544e059c27b1f5828314b4 <addf5e297e6cbf5341f9c07720693ca9ba0057b5

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5CISA ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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

CWE-416Use After Free

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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