CVE-2026-74276

Driver lockup via miscounted receive FIFO

Published Aug 15, 2026 · Updated Aug 15, 2026

Denial of service in the Linux Xilinx SPI driver allows local users to lock the driver through a FIFO-sized IRQ-mode transfer. The FIFO-sizing probe counts the hardware shift register as an extra FIFO slot, so receive capacity is overestimated by one and the final receive byte is lost. A transfer at least as large as the FIFO on a Xilinx SPI controller in IRQ mode leaves the receive counter nonzero while the FIFO remains empty, causing an endless polling loop.

CVSS severity5.5
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux Xilinx SPI driver allows local users to lock the driver through a FIFO-sized IRQ-mode transfer. The FIFO-sizing probe counts the hardware shift register as an extra FIFO slot, so receive capacity is overestimated by one and the final receive byte is lost. A transfer at least as large as the FIFO on a Xilinx SPI controller in IRQ mode leaves the receive counter nonzero while the FIFO remains empty, causing an endless polling loop.

The record

CVE
CVE-2026-74276
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-835, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=4.0
  2. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <1c9246a199e19b2fd36e94feed60e55f27103a4f
  3. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <1fc6a6c0cc7796b0c1cf4eec3f0720f422f09273
  4. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <47f3b5365536e8c38f264824ab15fdb74454e066
  5. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <4ee65558a7fda463222f5edc631b6d7862218725
  6. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <d1944b71c18e7494756bff1a6f80c25be99eaecb
  7. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <d7ccd8736b67550eca746ed7fa39a36016ff114b
  8. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <dfab0d4698a642bab9b895e2e6d240838cfe2cc6
  9. Affected versionversion=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <e98f589d54068dfcc7da42d9b730e47b84e2991a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.0; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <1c9246a199e19b2fd36e94feed60e55f27103a4f; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <1fc6a6c0cc7796b0c1cf4eec3f0720f422f09273; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <47f3b5365536e8c38f264824ab15fdb74454e066; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <4ee65558a7fda463222f5edc631b6d7862218725; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <d1944b71c18e7494756bff1a6f80c25be99eaecb; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <d7ccd8736b67550eca746ed7fa39a36016ff114b; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <dfab0d4698a642bab9b895e2e6d240838cfe2cc6; version=4c9a761402d780b86b9b068aba4ef8e29ed15e99 <e98f589d54068dfcc7da42d9b730e47b84e2991a

Published CVSS scores

5.5Red HatCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
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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