CVE-2026-64254

Local denial of service via offset BAR unmapping

Published Jul 24, 2026 · Updated Jul 24, 2026

Reachable assertion in the Linux kernel NTB EPF driver allows local users to interrupt service during module teardown. In ntb_epf_pci_remove, teardown calls pci_iounmap on the shared BAR mapping a second time through a PEER_SPAD-derived offset, so vunmap cannot find the offset address and raises a kernel warning. Exploitation requires local low-privileged access, the NTB endpoint-function driver, and PEER_SPAD and CONFIG sharing one PCI BAR; the published impact is loss of availability, with no confidentiality or integrity impact.

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 the Linux kernel NTB EPF driver allows local users to interrupt service during module teardown. In ntb_epf_pci_remove, teardown calls pci_iounmap on the shared BAR mapping a second time through a PEER_SPAD-derived offset, so vunmap cannot find the offset address and raises a kernel warning. Exploitation requires local low-privileged access, the NTB endpoint-function driver, and PEER_SPAD and CONFIG sharing one PCI BAR; the published impact is loss of availability, with no confidentiality or integrity impact.

The record

CVE
CVE-2026-64254
Published
Jul 24, 2026
Updated
Jul 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-617, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 24, 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=6.0
  2. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <06f6dd2ff2bd07eaf7178a807407ff27e85122b4
  3. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <81371dbd23601f67f01372817fdbab42c5601e43
  4. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <9764a786ba98db58f0725913c369e721253aba33
  5. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <a4be4a1308f02bff79a30eea2d04ead5b63685f2
  6. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <d876153680e3d721d385e554def919bce3d18c74
  7. Affected versionversion=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <eb47b9bffd07a47b84910847cb5ea066ce184055

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.0; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <06f6dd2ff2bd07eaf7178a807407ff27e85122b4; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <81371dbd23601f67f01372817fdbab42c5601e43; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <9764a786ba98db58f0725913c369e721253aba33; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <a4be4a1308f02bff79a30eea2d04ead5b63685f2; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <d876153680e3d721d385e554def919bce3d18c74; version=e75d5ae8ab88b7ffb3d1d56124b003f3555f74b4 <eb47b9bffd07a47b84910847cb5ea066ce184055

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499Endpoint Denial of Service

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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