CVE-2026-98441

Use-after-free via shared conntrack extension reallocation

Published Oct 18, 2026 · Updated Oct 18, 2026

Use-after-free in Linux act_ct allows attackers to trigger invalid kernel memory access through cloned packet processing. In tcf_ct_act(), extending a shared unconfirmed conntrack entry for labels or NAT invalidates a helper expectation-list pointer later used during destruction. Triggering requires both clones to revisit conntrack in the same zone without relevant packet changes; upstream identifies no practical networking pipeline requiring this sequence and establishes no broader exploitation outcome.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux act_ct allows attackers to trigger invalid kernel memory access through cloned packet processing. In tcf_ct_act(), extending a shared unconfirmed conntrack entry for labels or NAT invalidates a helper expectation-list pointer later used during destruction. Triggering requires both clones to revisit conntrack in the same zone without relevant packet changes; upstream identifies no practical networking pipeline requiring this sequence and establishes no broader exploitation outcome.

The record

CVE
CVE-2026-98441
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
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

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=6.2
  2. Affected versionversion=a21b06e7319129994f339ed47f512bbe57b77f5b <2b783c562c3238ff50c34fd7a72a735c9cc73d9a
  3. Affected versionversion=a21b06e7319129994f339ed47f512bbe57b77f5b <4a04ed91575819fb1859311113e95700b709bec7
  4. Affected versionversion=a21b06e7319129994f339ed47f512bbe57b77f5b <b097d9d7a5b09c8ec5c4c1a08e35ac5a66b06b44
  5. Affected versionversion=a21b06e7319129994f339ed47f512bbe57b77f5b <f85009dfcd65e5969526b0db7a49b5413746e630

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.2; version=a21b06e7319129994f339ed47f512bbe57b77f5b <2b783c562c3238ff50c34fd7a72a735c9cc73d9a; version=a21b06e7319129994f339ed47f512bbe57b77f5b <4a04ed91575819fb1859311113e95700b709bec7; version=a21b06e7319129994f339ed47f512bbe57b77f5b <b097d9d7a5b09c8ec5c4c1a08e35ac5a66b06b44; version=a21b06e7319129994f339ed47f512bbe57b77f5b <f85009dfcd65e5969526b0db7a49b5413746e630

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)
VectorUnavailable
PrivilegesUnavailable
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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