CVE-2026-74492

Kernel privilege escalation via shared comment use-after-free

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the Linux netfilter ipset subsystem allows attackers to gain kernel privileges through packet-side set updates. During hash-set resizing, mtype_resize() copies comment pointers while mtype_add() frees the shared comment for a packet-side add, leaving the replacement entry stale and later passing it to strlen(). Triggering requires a comment-enabled hash set, an installed SET --add-set --exist rule, and concurrent resize activity; exploitation can disclose or overwrite kernel memory or crash the host.

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 netfilter ipset subsystem allows attackers to gain kernel privileges through packet-side set updates. During hash-set resizing, mtype_resize() copies comment pointers while mtype_add() frees the shared comment for a packet-side add, leaving the replacement entry stale and later passing it to strlen(). Triggering requires a comment-enabled hash set, an installed SET --add-set --exist rule, and concurrent resize activity; exploitation can disclose or overwrite kernel memory or crash the host.

The record

CVE
CVE-2026-74492
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
unauthenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=5.4.24 <5.5
  2. Affected versionversion=5.5.8 <5.6
  3. Affected versionversion=5.6
  4. Affected versionversion=5dd9488ae41070b69d2f4acb580f77db5705f9ca
  5. Affected versionversion=a469bab3386aebff33c59506f3a95e35b91118fd
  6. Affected versionversion=f66ee0410b1c3481ee75e5db9b34547b4d582465 <4ae701848e4ba9e9713375fb7d82218cbd309da2
  7. Affected versionversion=f66ee0410b1c3481ee75e5db9b34547b4d582465 <661ff9c0cfbe07f8eed920dde9f7781491738207
  8. Affected versionversion=f66ee0410b1c3481ee75e5db9b34547b4d582465 <77dbb248a5cc7a5270cd37bbb0b635bf059a872a
  9. Affected versionversion=f66ee0410b1c3481ee75e5db9b34547b4d582465 <c710e9bf38e4e71a8db85d26a0f70c0674664207
  10. Affected versionversion=f66ee0410b1c3481ee75e5db9b34547b4d582465 <f30415929be8aeb002d557c8d3f7ab2d2188003a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.4.24 <5.5; version=5.5.8 <5.6; version=5.6; version=5dd9488ae41070b69d2f4acb580f77db5705f9ca; version=a469bab3386aebff33c59506f3a95e35b91118fd; version=f66ee0410b1c3481ee75e5db9b34547b4d582465 <4ae701848e4ba9e9713375fb7d82218cbd309da2; version=f66ee0410b1c3481ee75e5db9b34547b4d582465 <661ff9c0cfbe07f8eed920dde9f7781491738207; version=f66ee0410b1c3481ee75e5db9b34547b4d582465 <77dbb248a5cc7a5270cd37bbb0b635bf059a872a; version=f66ee0410b1c3481ee75e5db9b34547b4d582465 <c710e9bf38e4e71a8db85d26a0f70c0674664207; version=f66ee0410b1c3481ee75e5db9b34547b4d582465 <f30415929be8aeb002d557c8d3f7ab2d2188003a

Published CVSS scores

7.0OracleCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.4Linux CNACVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.8Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/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.

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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