CVE-2026-23398Public exploit

Kernel panic via unchecked sparse protocol handler

Published Mar 26, 2026 · Updated Mar 26, 2026

NULL pointer dereference in affected Linux Kernel releases from 3.14 allows remote attackers to crash the kernel via a crafted ICMP error. The icmp_tag_validation() function dereferences the sparse inet_protos[proto] entry without checking whether an inner protocol number has a registered handler. Reachability requires hardened PMTU mode (ip_no_pmtu_disc=3) and Layer 3 adjacency; the softirq-context fault triggers a kernel panic.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in affected Linux Kernel releases from 3.14 allows remote attackers to crash the kernel via a crafted ICMP error. The icmp_tag_validation() function dereferences the sparse inet_protos[proto] entry without checking whether an inner protocol number has a registered handler. Reachability requires hardened PMTU mode (ip_no_pmtu_disc=3) and Layer 3 adjacency; the softirq-context fault triggers a kernel panic.

The record

CVE
CVE-2026-23398
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 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=3.14
  2. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <1e4e2f5e48cec0cccaea9815fb9486c084ba41e2
  3. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161
  4. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <614aefe56af8e13331e50220c936fc0689cf5675
  5. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <9647e99d2a617c355d2b378be0ff6d0e848fd579
  6. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <b61529c357f1ee4d64836eb142a542d2e7ad67ce
  7. Affected versionversion=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <d938dd5a0ad780c891ea3bc94cae7405f11e618a

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.14; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <1e4e2f5e48cec0cccaea9815fb9486c084ba41e2; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <614aefe56af8e13331e50220c936fc0689cf5675; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <9647e99d2a617c355d2b378be0ff6d0e848fd579; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <b61529c357f1ee4d64836eb142a542d2e7ad67ce; version=8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e <d938dd5a0ad780c891ea3bc94cae7405f11e618a

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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