CVE-2026-99081

Transmit timeouts via undersized DMA mappings

Published Oct 23, 2026 · Updated Oct 23, 2026

DMA overread in Linux bnxt_en allows attackers to interrupt network transmission via packets padded beyond their DMA mapping. The bnxt_start_xmit() function pads short frames to 52 bytes but maps the original length, instructing the NIC to read beyond the mapped buffer. Reported VLAN/macvlan traffic on BCM57412 NICs triggers IOMMU faults and transmit queue timeouts when that read crosses a page boundary; attacker reachability is not established.

CVSS severityUnavailable
Unscored
EPSS probability0.52%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DMA overread in Linux bnxt_en allows attackers to interrupt network transmission via packets padded beyond their DMA mapping. The bnxt_start_xmit() function pads short frames to 52 bytes but maps the original length, instructing the NIC to read beyond the mapped buffer. Reported VLAN/macvlan traffic on BCM57412 NICs triggers IOMMU faults and transmit queue timeouts when that read crosses a page boundary; attacker reachability is not established.

The record

CVE
CVE-2026-99081
Published
Oct 23, 2026
Updated
Oct 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 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=4.4
  2. Affected versionversion=c0c050c58d840994ba842ad1c338a98e7c12b764 <2956aca14dd2977cd08bd2ccafae3beb8b84b268
  3. Affected versionversion=c0c050c58d840994ba842ad1c338a98e7c12b764 <5213f65a9667d3dd85db2e6df8f2e0516290db34
  4. Affected versionversion=c0c050c58d840994ba842ad1c338a98e7c12b764 <a51d233ccd4889aadb71dace863525cc2b00271e
  5. Affected versionversion=c0c050c58d840994ba842ad1c338a98e7c12b764 <cf8530a25ae92c4493e2f22981ecb46f0b66f4c8
  6. Affected versionversion=c0c050c58d840994ba842ad1c338a98e7c12b764 <fbd977e513971ccb4f0762a7f59eac500e474f89

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.4; version=c0c050c58d840994ba842ad1c338a98e7c12b764 <2956aca14dd2977cd08bd2ccafae3beb8b84b268; version=c0c050c58d840994ba842ad1c338a98e7c12b764 <5213f65a9667d3dd85db2e6df8f2e0516290db34; version=c0c050c58d840994ba842ad1c338a98e7c12b764 <a51d233ccd4889aadb71dace863525cc2b00271e; version=c0c050c58d840994ba842ad1c338a98e7c12b764 <cf8530a25ae92c4493e2f22981ecb46f0b66f4c8; version=c0c050c58d840994ba842ad1c338a98e7c12b764 <fbd977e513971ccb4f0762a7f59eac500e474f89

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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