CVE-2026-43011Network attack vector

Remote memory corruption via X.25 skb double free

Published May 1, 2026 · Updated May 1, 2026

Double free in the Linux kernel X.25 receive path allows remote attackers to corrupt kernel memory during frame processing. When x25_queue_rx_frame frees an skb after alloc_skb fails, its error becomes a zero queued result that makes x25_backlog_rcv free the same skb again. The condition requires X.25 traffic and an alloc_skb failure; resulting memory corruption can crash the kernel or compromise data confidentiality and integrity.

CVSS severity9.8
Critical
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in the Linux kernel X.25 receive path allows remote attackers to corrupt kernel memory during frame processing. When x25_queue_rx_frame frees an skb after alloc_skb fails, its error becomes a zero queued result that makes x25_backlog_rcv free the same skb again. The condition requires X.25 traffic and an alloc_skb failure; resulting memory corruption can crash the kernel or compromise data confidentiality and integrity.

The record

CVE
CVE-2026-43011
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-415, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f5e3005984645bf5bd129c6b13149879580b1fb
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <524371398d8463ea7e101fce2cbf3915645d1730
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c87dd137c0dad07cc55f98181ff380b0c23d2878
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d10a26aa4d072320530e6968ef945c8c575edf61
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f782dd382203b2a8c4552a628431b7de65a19a7b
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fa1dbc93530b34fab0da9862426fe9c918c74dc0
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3f5e3005984645bf5bd129c6b13149879580b1fb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <524371398d8463ea7e101fce2cbf3915645d1730; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c87dd137c0dad07cc55f98181ff380b0c23d2878; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d10a26aa4d072320530e6968ef945c8c575edf61; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f782dd382203b2a8c4552a628431b7de65a19a7b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fa1dbc93530b34fab0da9862426fe9c918c74dc0; version=2.6.12

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1499Endpoint Denial of Service

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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