CVE-2023-53559

Kernel crash via overwritten skb control buffer

Published Oct 4, 2025 · Updated Oct 4, 2025

Use-after-free in the Linux ip_vti transmit path allows local users to crash the kernel through crafted VTI IPv6 traffic. The path passes xfrm_decode_session an skb control buffer that an sfb qdisc can overwrite, leaving IP6CB(skb)->nhoff unset and causing decode_session6 to read freed or adjacent slab memory. Exploitation requires locally configuring a VTI device and sfb qdisc, then routing IPv6 packets through it; repeated packets can sustain a crash and the invalid read can disclose kernel-heap data.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux ip_vti transmit path allows local users to crash the kernel through crafted VTI IPv6 traffic. The path passes xfrm_decode_session an skb control buffer that an sfb qdisc can overwrite, leaving IP6CB(skb)->nhoff unset and causing decode_session6 to read freed or adjacent slab memory. Exploitation requires locally configuring a VTI device and sfb qdisc, then routing IPv6 packets through it; repeated packets can sustain a crash and the invalid read can disclose kernel-heap data.

The record

CVE
CVE-2023-53559
Published
Oct 4, 2025
Updated
Oct 4, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 2025Record 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=3.19
  2. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <0b4d69539fdea138af2befe08893850c89248068
  3. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <2b05bf5dc437f7891dd409a3eaf5058459391c7a
  4. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <6018a266279b1a75143c7c0804dd08a5fc4c3e0b
  5. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <78e397a43e1c47321a4679cc49a6c4530bf820b9
  6. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <7dfe23659f3677c08a60a0056cda2d91a79c15ca
  7. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <82fb41c5de243e7dfa90f32ca58e35adaff56c1d
  8. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <d34c30442d5e53a33cde79ca163320dbe2432cbd
  9. Affected versionversion=f855691975bb06373a98711e4cfe2c224244b536 <e1e04cc2ef2c0c0866c19f5627149a76c2baae32

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.19; version=f855691975bb06373a98711e4cfe2c224244b536 <0b4d69539fdea138af2befe08893850c89248068; version=f855691975bb06373a98711e4cfe2c224244b536 <2b05bf5dc437f7891dd409a3eaf5058459391c7a; version=f855691975bb06373a98711e4cfe2c224244b536 <6018a266279b1a75143c7c0804dd08a5fc4c3e0b; version=f855691975bb06373a98711e4cfe2c224244b536 <78e397a43e1c47321a4679cc49a6c4530bf820b9; version=f855691975bb06373a98711e4cfe2c224244b536 <7dfe23659f3677c08a60a0056cda2d91a79c15ca; version=f855691975bb06373a98711e4cfe2c224244b536 <82fb41c5de243e7dfa90f32ca58e35adaff56c1d; version=f855691975bb06373a98711e4cfe2c224244b536 <d34c30442d5e53a33cde79ca163320dbe2432cbd; version=f855691975bb06373a98711e4cfe2c224244b536 <e1e04cc2ef2c0c0866c19f5627149a76c2baae32

Published CVSS scores

7.8Linux Kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
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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