CVE-2026-98643Public exploit

Kernel-memory disclosure via unchecked rtt_min socket cast

Published Oct 18, 2026 · Updated Oct 18, 2026

Out-of-bounds reading in Linux sock_ops allows local users to read adjacent kernel memory through the rtt_min context field. The context rewrite casts a request_sock to tcp_sock without checking is_locked_tcp_sock, then loads rtt_min beyond the smaller allocation. Exploitation requires a running sockops program reading that field during BPF_SOCK_OPS_RWND_INIT on the TCP connection-request path; the demonstrated disclosure includes a kernel pointer fragment.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds reading in Linux sock_ops allows local users to read adjacent kernel memory through the rtt_min context field. The context rewrite casts a request_sock to tcp_sock without checking is_locked_tcp_sock, then loads rtt_min beyond the smaller allocation. Exploitation requires a running sockops program reading that field during BPF_SOCK_OPS_RWND_INIT on the TCP connection-request path; the demonstrated disclosure includes a kernel pointer fragment.

The record

CVE
CVE-2026-98643
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=4.16
  2. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <0c796efa919f52f788c22c79d1f1b70321696b3d
  3. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <3a46f14e6cf375f3ca38f8f6e6524749e24ea0a8
  4. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <6785313d4fac96afb21ef193610c1fa88b1a9e64
  5. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <75f8cf22463d82bb1fb0239a3d485fc8f4c8ef03
  6. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <a8a9becbac93a9f54f4d565f1f3005eb08a7912f
  7. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <cba54d142c43ec96d8c4d566f66439e8c0afded7
  8. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <fc9d0e6e9d86fbefe7b8fe6ee49f4cf102add79d
  9. Affected versionversion=44f0e43037d3a17b043843ba67610ac7c7e37db6 <fd6bf2721933d8c90bc4ce57f3e204c9295e7e3f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <0c796efa919f52f788c22c79d1f1b70321696b3d; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <3a46f14e6cf375f3ca38f8f6e6524749e24ea0a8; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <6785313d4fac96afb21ef193610c1fa88b1a9e64; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <75f8cf22463d82bb1fb0239a3d485fc8f4c8ef03; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <a8a9becbac93a9f54f4d565f1f3005eb08a7912f; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <cba54d142c43ec96d8c4d566f66439e8c0afded7; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <fc9d0e6e9d86fbefe7b8fe6ee49f4cf102add79d; version=44f0e43037d3a17b043843ba67610ac7c7e37db6 <fd6bf2721933d8c90bc4ce57f3e204c9295e7e3f

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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