CVE-2026-74569Network attack vector

Remote kernel memory exposure via SIP delta wrap

Published Aug 15, 2026 · Updated Aug 15, 2026

Out-of-bounds read in the Linux kernel allows remote attackers to expose kernel memory or crash systems via crafted TCP SIP traffic. sip_help_tcp() stores NAT rewrite growth in signed 16-bit diff and tdiff values; expansion beyond S16_MAX wraps the delta, produces a huge unsigned datalen, and makes ct_sip_get_header() read past the skb tail. Exploitation requires the SIP conntrack and NAT helpers on a traversing TCP SIP flow; the bounded consequences are a kernel-memory read and a kernel crash.

CVSS severity9.8
Critical
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux kernel allows remote attackers to expose kernel memory or crash systems via crafted TCP SIP traffic. sip_help_tcp() stores NAT rewrite growth in signed 16-bit diff and tdiff values; expansion beyond S16_MAX wraps the delta, produces a huge unsigned datalen, and makes ct_sip_get_header() read past the skb tail. Exploitation requires the SIP conntrack and NAT helpers on a traversing TCP SIP flow; the bounded consequences are a kernel-memory read and a kernel crash.

The record

CVE
CVE-2026-74569
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1499.004
Attack vector
network
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

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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=2.6.34
  2. Affected versionversion=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <63eea41759fd682229c14e0a2205802b46d106f3
  3. Affected versionversion=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <c97621a110e386b2dd69e276eb699e1d3cec581d
  4. Affected versionversion=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5
  5. Affected versionversion=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64
  6. Affected versionversion=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <f74554e67ccf04d1fa71069e8c9afa2717e40716

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.34; version=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <63eea41759fd682229c14e0a2205802b46d106f3; version=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <c97621a110e386b2dd69e276eb699e1d3cec581d; version=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5; version=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64; version=f5b321bd37fbec9188feb1f721ab46a5ac0b35da <f74554e67ccf04d1fa71069e8c9afa2717e40716

Published CVSS scores

7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
9.8CVE.orgCVSS:3.1/AV:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application 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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