CVE-2026-23380

Local denial of service via copied tracing VMA

Published Mar 25, 2026 · Updated Mar 25, 2026

Reachable assertion in Linux Kernel 6.10 allows local users to disrupt availability by forking a copied tracing-buffer mapping. The tracing VMA open path copies the mapping without incrementing user_mapped, so parent and child closes decrement it twice and the second close triggers WARN_ON. The local user must apply MADVISE_DOFORK to override VM_DONTCOPY before forking; the resulting warning can interrupt service, particularly when panic_on_warn is enabled.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in Linux Kernel 6.10 allows local users to disrupt availability by forking a copied tracing-buffer mapping. The tracing VMA open path copies the mapping without incrementing user_mapped, so parent and child closes decrement it twice and the second close triggers WARN_ON. The local user must apply MADVISE_DOFORK to override VM_DONTCOPY before forking; the resulting warning can interrupt service, particularly when panic_on_warn is enabled.

The record

CVE
CVE-2026-23380
Published
Mar 25, 2026
Updated
Mar 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 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=6.10
  2. Affected versionversion=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <91f3e8d84c89918769e71393f839c9fefadc2580
  3. Affected versionversion=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0
  4. Affected versionversion=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <cdd96641b64297a2db42676f051362b76280a58b
  5. Affected versionversion=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.10; version=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <91f3e8d84c89918769e71393f839c9fefadc2580; version=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <b0f269ba6fefe9e3cb9feedcf78fcd0b633800c0; version=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <cdd96641b64297a2db42676f051362b76280a58b; version=cf9f0f7c4c5bb45e7bb270e48bab6f7837825a64 <e39bb9e02b68942f8e9359d2a3efe7d37ae6be0e

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

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

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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