CVE-2026-72400

Kernel memory read via undersized SEG6 header

Published Aug 15, 2026 · Updated Aug 15, 2026

Out-of-bounds read in affected Linux kernel versions allows local users to read adjacent kernel memory through an undersized BPF SEG6 header. seg6_validate_srh() reads fixed ipv6_sr_hdr fields before confirming that the caller-supplied length covers the structure. Triggering the read requires locally loading and attaching a BPF LWT SEG6 program and supplying a two-byte encapsulation header; remote IPv6 traffic alone does not reach the flaw.

CVSS severity7.8
High
EPSS probability0.17%
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 affected Linux kernel versions allows local users to read adjacent kernel memory through an undersized BPF SEG6 header. seg6_validate_srh() reads fixed ipv6_sr_hdr fields before confirming that the caller-supplied length covers the structure. Triggering the read requires locally loading and attaching a BPF LWT SEG6 program and supplying a two-byte encapsulation header; remote IPv6 traffic alone does not reach the flaw.

The record

CVE
CVE-2026-72400
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

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=4.18
  2. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <071f1a38d7ddbadee29c09b9e3ee0ff3a61e6a0e
  3. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <0fc7069d39239978130c37ebceaec85c8948d3f1
  4. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <715eb12e453df752f1b4baaf972c3acff0ab9402
  5. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <7247d05c987c3eec4bb7c2306dbd77ecdf3b7c73
  6. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <804bb969f194c93497ba632b98343794c6367fdc
  7. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <8dba7a94a269b88e500aafc25ad567ef6a423698
  8. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <a75d99f46bf21b45965ce39c5cfb3b8bb5ffb1aa
  9. Affected versionversion=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <c9961336aa5ff83092f23e33ee86666a9dbd1b2a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.18; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <071f1a38d7ddbadee29c09b9e3ee0ff3a61e6a0e; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <0fc7069d39239978130c37ebceaec85c8948d3f1; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <715eb12e453df752f1b4baaf972c3acff0ab9402; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <7247d05c987c3eec4bb7c2306dbd77ecdf3b7c73; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <804bb969f194c93497ba632b98343794c6367fdc; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <8dba7a94a269b88e500aafc25ad567ef6a423698; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <a75d99f46bf21b45965ce39c5cfb3b8bb5ffb1aa; version=fe94cc290f535709d3c5ebd1e472dfd0aec7ee79 <c9961336aa5ff83092f23e33ee86666a9dbd1b2a

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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