CVE-2026-74589

Kernel memory compromise via sockmap reference race

Published Aug 22, 2026 · Updated Aug 25, 2026

Use-after-free in the Linux kernel sockmap send-verdict path allows attackers to compromise kernel memory via concurrent sendmsg calls. tcp_bpf_send_verdict copies psock->sk_redir under the source socket lock but drops the lock without taking a reference, allowing a second sender to free that socket before tcp_bpf_sendmsg_redir dereferences it. Triggering the race requires concurrent sends on the same sockmap-attached TCP socket while a cached redirect verdict retains nonzero apply_bytes; the stale dereference can expose or corrupt kernel memory or crash the kernel.

CVSS severity8.4
High
EPSS probability0.14%
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 sockmap send-verdict path allows attackers to compromise kernel memory via concurrent sendmsg calls. tcp_bpf_send_verdict copies psock->sk_redir under the source socket lock but drops the lock without taking a reference, allowing a second sender to free that socket before tcp_bpf_sendmsg_redir dereferences it. Triggering the race requires concurrent sends on the same sockmap-attached TCP socket while a cached redirect verdict retains nonzero apply_bytes; the stale dereference can expose or corrupt kernel memory or crash the kernel.

The record

CVE
CVE-2026-74589
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=4.20
  2. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <1cec526cf0a2227395f2c2f4b671cb052ff0b00e
  3. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <41b7da0cb72ca5aa1e62b68dab323d0791fc6bdf
  4. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <4c9d9aa809c261dc0490a0e19d675f7e8e4c85bf
  5. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <90a19b0894ba79a699b48cf44421b36fbd566e99
  6. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <9b4fbc371a6ecf1b4e43b5a629015cc0830d8de3
  7. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <a14e4ef1d90c3418f01b3b6b8fd3a40a0a208a10
  8. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <a76624733730e541e4955fdecf506af2f6b20558
  9. Affected versionversion=604326b41a6fb9b4a78b6179335decee0365cd8c <d192cff2a37d59206dabe6ec2e60ceac6271f274

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.20; version=604326b41a6fb9b4a78b6179335decee0365cd8c <1cec526cf0a2227395f2c2f4b671cb052ff0b00e; version=604326b41a6fb9b4a78b6179335decee0365cd8c <41b7da0cb72ca5aa1e62b68dab323d0791fc6bdf; version=604326b41a6fb9b4a78b6179335decee0365cd8c <4c9d9aa809c261dc0490a0e19d675f7e8e4c85bf; version=604326b41a6fb9b4a78b6179335decee0365cd8c <90a19b0894ba79a699b48cf44421b36fbd566e99; version=604326b41a6fb9b4a78b6179335decee0365cd8c <9b4fbc371a6ecf1b4e43b5a629015cc0830d8de3; version=604326b41a6fb9b4a78b6179335decee0365cd8c <a14e4ef1d90c3418f01b3b6b8fd3a40a0a208a10; version=604326b41a6fb9b4a78b6179335decee0365cd8c <a76624733730e541e4955fdecf506af2f6b20558; version=604326b41a6fb9b4a78b6179335decee0365cd8c <d192cff2a37d59206dabe6ec2e60ceac6271f274

Published CVSS scores

8.4LinuxCVSS:3.1/AV:L/AC:L/PR:N/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
Privilegesunauthenticated
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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