CVE-2026-72391

Kernel memory exhaustion via leaked SFP buses

Published Aug 15, 2026 · Updated Aug 15, 2026

Memory leak in the Linux kernel 6.1 SFP driver allows physically proximate attackers to consume kernel memory by removing an SFP module. sfp_i2c_mdiobus_destroy unregisters an I2C MDIO bus and clears the final pointer without calling mdiobus_free, leaving the allocated mii_bus structure resident. The trigger requires hot-removal of a copper or RollBall SFP module that instantiated an MDIO bus, and repeated removals can reduce availability by retaining kernel memory.

CVSS severity2.4
Low
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux kernel 6.1 SFP driver allows physically proximate attackers to consume kernel memory by removing an SFP module. sfp_i2c_mdiobus_destroy unregisters an I2C MDIO bus and clears the final pointer without calling mdiobus_free, leaving the allocated mii_bus structure resident. The trigger requires hot-removal of a copper or RollBall SFP module that instantiated an MDIO bus, and repeated removals can reduce availability by retaining kernel memory.

The record

CVE
CVE-2026-72391
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
physical
Privileges
unauthenticated

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=6.1
  2. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <2381bf3f484e8e4fd89a225445872ec14e036ab5
  3. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <3183b6f5510c876a1c4b4a6bdc3d0ad8940fe742
  4. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <86d379fcf1b79bdf4bc2ac891297f30f63d041d8
  5. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <8f31efff9206f9f0adb853cad6916086aac4d5ef
  6. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <92dd9a522f01ef57f633a8c1953cf6d48ef2bcd5
  7. Affected versionversion=e85b1347ace677c3822c12d9332dfaaffe594da6 <d2c37f26d1a37f8177be5f354537f8ee3ec31cc2

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.1; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <2381bf3f484e8e4fd89a225445872ec14e036ab5; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <3183b6f5510c876a1c4b4a6bdc3d0ad8940fe742; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <86d379fcf1b79bdf4bc2ac891297f30f63d041d8; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <8f31efff9206f9f0adb853cad6916086aac4d5ef; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <92dd9a522f01ef57f633a8c1953cf6d48ef2bcd5; version=e85b1347ace677c3822c12d9332dfaaffe594da6 <d2c37f26d1a37f8177be5f354537f8ee3ec31cc2

Published CVSS scores

2.4SUSECVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
2.4Amazon LinuxCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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)
Vectorphysical
Privilegesunauthenticated
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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