CVE-2026-31691

Persistent transmit stall via NAPI synchronization deadlock

Published Apr 27, 2026 · Updated Apr 27, 2026

Denial of service in Linux Kernel 6.14 on affected branches allows local users to permanently stall an igb transmit queue after an AF_XDP exit. After the XSK pool is destroyed, igb_clean_rx_irq_zc() keeps returning the full budget, so napi_complete_done() never clears NAPI_STATE_SCHED and igb_down() spins in napi_synchronize(). Triggering the persistent stall requires an igb interface using AF_XDP zero-copy, abrupt application termination, and a subsequent interface shutdown.

CVSS severityUnavailable
Unscored
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

Denial of service in Linux Kernel 6.14 on affected branches allows local users to permanently stall an igb transmit queue after an AF_XDP exit. After the XSK pool is destroyed, igb_clean_rx_irq_zc() keeps returning the full budget, so napi_complete_done() never clears NAPI_STATE_SCHED and igb_down() spins in napi_synchronize(). Triggering the persistent stall requires an igb interface using AF_XDP zero-copy, abrupt application termination, and a subsequent interface shutdown.

The record

CVE
CVE-2026-31691
Published
Apr 27, 2026
Updated
Apr 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 27, 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?

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  1. Affected versionversion=2c6196013f84651772388a86dfd4bb033d0c0d45 <27f5997686ee7fb7ac01be72b2010f168a3409fc
  2. Affected versionversion=2c6196013f84651772388a86dfd4bb033d0c0d45 <4700471775746058c962ded6e659bf908fd76e13
  3. Affected versionversion=2c6196013f84651772388a86dfd4bb033d0c0d45 <b1e067240379f950a0022208e0685f3465c211cb
  4. Affected versionversion=6.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2c6196013f84651772388a86dfd4bb033d0c0d45 <27f5997686ee7fb7ac01be72b2010f168a3409fc; version=2c6196013f84651772388a86dfd4bb033d0c0d45 <4700471775746058c962ded6e659bf908fd76e13; version=2c6196013f84651772388a86dfd4bb033d0c0d45 <b1e067240379f950a0022208e0685f3465c211cb; version=6.14

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

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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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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