CVE-2026-98803Hinoki check available

DMA faults via unmapped receive buffers

Published Oct 18, 2026 · Updated Oct 18, 2026

DMA mapping errors in Linux stmmac allow attackers to trigger SMMU translation faults via oversized received Ethernet frames. The stmmac_init_rx_buffers() and stmmac_rx_refill() paths leave the secondary buffer unbacked outside split-header mode, so DMA writes beyond the first buffer target an unmapped address. An accepted frame must exceed dma_buf_sz on affected hardware; the documented consequence on IOMMU-based platforms is a translation fault, not a demonstrated system crash.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

DMA mapping errors in Linux stmmac allow attackers to trigger SMMU translation faults via oversized received Ethernet frames. The stmmac_init_rx_buffers() and stmmac_rx_refill() paths leave the secondary buffer unbacked outside split-header mode, so DMA writes beyond the first buffer target an unmapped address. An accepted frame must exceed dma_buf_sz on affected hardware; the documented consequence on IOMMU-based platforms is a translation fault, not a demonstrated system crash.

The record

CVE
CVE-2026-98803
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=5.4.262 <5.5
  2. Affected versionversion=5.5
  3. Affected versionversion=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <358d5ac5a5d57ce21c3814c4e3e8f3fbcb7304b4
  4. Affected versionversion=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <88095728511e0df9c89528944f5a1762ad298983
  5. Affected versionversion=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <a7cff44543f66f3a19151060cb549691d191d44c
  6. Affected versionversion=c4b712d1a814a0535091d99e6cf04d69ac42ef7b

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.4.262 <5.5; version=5.5; version=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <358d5ac5a5d57ce21c3814c4e3e8f3fbcb7304b4; version=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <88095728511e0df9c89528944f5a1762ad298983; version=88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 <a7cff44543f66f3a19151060cb549691d191d44c; version=c4b712d1a814a0535091d99e6cf04d69ac42ef7b

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.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
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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