CVE-2026-23397

Kernel crash and memory disclosure via malformed fingerprints

Published Mar 26, 2026 · Updated Mar 26, 2026

Out-of-bounds read in the Linux Kernel nfnetlink_osf matcher allows local users to disclose kernel memory or crash the system. The nfnl_osf_add_callback() path accepts zero-length options and MSS options shorter than four bytes, after which nf_osf_match_one() dereferences a NULL option pointer or reads optp[2] and optp[3] beyond the declared option. Exploitation requires local low-privileged access and an active xt_osf packet-matching path; the bounded consequences are kernel-memory exposure and system interruption.

CVSS severity7.1
High
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

Out-of-bounds read in the Linux Kernel nfnetlink_osf matcher allows local users to disclose kernel memory or crash the system. The nfnl_osf_add_callback() path accepts zero-length options and MSS options shorter than four bytes, after which nf_osf_match_one() dereferences a NULL option pointer or reads optp[2] and optp[3] beyond the declared option. Exploitation requires local low-privileged access and an active xt_osf packet-matching path; the bounded consequences are kernel-memory exposure and system interruption.

The record

CVE
CVE-2026-23397
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1499.004
Attack vector
local
Privileges
authenticated

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=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <224f4678812e1a7bc8341bcb666773a0aec5ea6f
  2. Affected versionversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <3932620c04c2938c93c0890c225960d3d34ba355
  3. Affected versionversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6
  4. Affected versionversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <aa0574182c46963c3cdb8cde46ec93aca21100d8
  5. Affected versionversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <dbdfaae9609629a9569362e3b8f33d0a20fd783c
  6. Affected versionversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <ec8bf0571b142f29dc0b68ae2ac3952f7a464b38
  7. Affected versionversion=2.6.31

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <224f4678812e1a7bc8341bcb666773a0aec5ea6f; version=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <3932620c04c2938c93c0890c225960d3d34ba355; version=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6; version=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <aa0574182c46963c3cdb8cde46ec93aca21100d8; version=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <dbdfaae9609629a9569362e3b8f33d0a20fd783c; version=11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384 <ec8bf0571b142f29dc0b68ae2ac3952f7a464b38; version=2.6.31

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
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.

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Technologies

Your stack

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Your stack

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