CVE-2026-63831

Kernel memory corruption via shared-buffer in-place cryptography

Published Jul 19, 2026 · Updated Jul 19, 2026

Use-after-free in Linux Kernel mac802154 LLSEC allows physically proximate attackers to corrupt kernel memory via secured 802.15.4 frames. The LLSEC encrypt and decrypt helpers pass shared skb data as both source and destination to in-place crypto without first making the buffer private. The target must be running mac802154 with LLSEC enabled, and the attacker must possess valid LLSEC credentials within WPAN radio range; concurrent traffic can corrupt sibling packets or crash the kernel.

CVSS severity8.8
High
EPSS probability0.25%
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 Linux Kernel mac802154 LLSEC allows physically proximate attackers to corrupt kernel memory via secured 802.15.4 frames. The LLSEC encrypt and decrypt helpers pass shared skb data as both source and destination to in-place crypto without first making the buffer private. The target must be running mac802154 with LLSEC enabled, and the attacker must possess valid LLSEC credentials within WPAN radio range; concurrent traffic can corrupt sibling packets or crash the kernel.

The record

CVE
CVE-2026-63831
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <3a2b378b3a9ca75d3518d879148d2ad25b5714a9
  2. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <7a831bcd0486788283ef35e396d4282ee01bb0d5
  3. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <84a04eb5b210643bd67aab81ff805d32f62aa865
  4. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <86d531337ea1ba02d9f2bc830d07c683d9bfaade
  5. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <993fd674fe85d114e6a8d3963033d4fbbc2170a8
  6. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <bd968bdd568beacfdf98ec537a87527e85f1d0cf
  7. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <e28e7fd34c449028325322a3f5127b92594b7396
  8. Affected versionversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <ff976ef7c39199ebff33c18034636595016db9f0
  9. Affected versionversion=3.16

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <3a2b378b3a9ca75d3518d879148d2ad25b5714a9; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <7a831bcd0486788283ef35e396d4282ee01bb0d5; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <84a04eb5b210643bd67aab81ff805d32f62aa865; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <86d531337ea1ba02d9f2bc830d07c683d9bfaade; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <993fd674fe85d114e6a8d3963033d4fbbc2170a8; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <bd968bdd568beacfdf98ec537a87527e85f1d0cf; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <e28e7fd34c449028325322a3f5127b92594b7396; version=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <ff976ef7c39199ebff33c18034636595016db9f0; version=3.16

Published CVSS scores

8.8Linux kernel CNACVSS:3.1/AV:A/AC:L/PR:N/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)
Vectoradjacent
Privilegesauthenticated
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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