CVE-2026-74704Network attack vector

Conditional kernel panic via malformed IP headers

Published Aug 22, 2026 · Updated Aug 25, 2026

Denial of service in the Linux CAKE ACK filter allows remote attackers to trigger kernel warnings or a panic via malformed IP headers. In cake_ack_filter(), the parser reaches an unsupported IP-version branch that correctly skips the packet but still executes WARN_ON(1). The path requires CAKE ACK filtering on a backlogged flow; it floods the kernel log normally and crashes the host only when panic_on_warn is enabled.

CVSS severity8.2
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux CAKE ACK filter allows remote attackers to trigger kernel warnings or a panic via malformed IP headers. In cake_ack_filter(), the parser reaches an unsupported IP-version branch that correctly skips the packet but still executes WARN_ON(1). The path requires CAKE ACK filtering on a backlogged flow; it floods the kernel log normally and crashes the host only when panic_on_warn is enabled.

The record

CVE
CVE-2026-74704
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
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

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=4.19
  2. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <0c4882bff34558d8d53fb04c3e96da5c327c7dc8
  3. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <2504a76e5c0694e14e15562730e1339f2d9f9458
  4. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <2a33516f9ef59ad11844d4fc152f889449b5daf3
  5. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <a1ae353d8355407c1bea971d1c1af5e7f242bb7d
  6. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <a4b52612004a5639c4bfc30ba93ba414b8326e2a
  7. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <ae1b2f8e21a41e7c7e75511bea0c4ccc59ec1bd3
  8. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <c1693b7844a6c06d31a565e5a494948034dfd235
  9. Affected versionversion=8b7138814f29933898ecd31dfc83e35a30ee69f5 <cd2f1d9fe8a507c2dc86ad326fe221f121c47734

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.19; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <0c4882bff34558d8d53fb04c3e96da5c327c7dc8; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <2504a76e5c0694e14e15562730e1339f2d9f9458; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <2a33516f9ef59ad11844d4fc152f889449b5daf3; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <a1ae353d8355407c1bea971d1c1af5e7f242bb7d; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <a4b52612004a5639c4bfc30ba93ba414b8326e2a; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <ae1b2f8e21a41e7c7e75511bea0c4ccc59ec1bd3; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <c1693b7844a6c06d31a565e5a494948034dfd235; version=8b7138814f29933898ecd31dfc83e35a30ee69f5 <cd2f1d9fe8a507c2dc86ad326fe221f121c47734

Published CVSS scores

8.2UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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