CVE-2026-72373Network attack vector

System crash via unchecked callback volume lookup

Published Aug 15, 2026 · Updated Aug 15, 2026

NULL pointer dereference in the Linux kernel AFS client from 5.8 allows remote attackers to crash the system via a callback RPC. afs_break_some_callbacks() passes a NULL result from afs_lookup_volume_rcu() to afs_break_volume_callback(), which dereferences volume->servers. Reachability requires a mounted AFS client and an encrypted callback channel from a known AFS fileserver; impact is limited to a kernel oops or panic requiring reboot.

CVSS severity7.5
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel AFS client from 5.8 allows remote attackers to crash the system via a callback RPC. afs_break_some_callbacks() passes a NULL result from afs_lookup_volume_rcu() to afs_break_volume_callback(), which dereferences volume->servers. Reachability requires a mounted AFS client and an encrypted callback channel from a known AFS fileserver; impact is limited to a kernel oops or panic requiring reboot.

The record

CVE
CVE-2026-72373
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.8
  2. Affected versionversion=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <5492799ec5d27be3bd454dcaf046bc7054f637ae
  3. Affected versionversion=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <794a01110390c1b76f59ece773fb0fbfd89c6f5c
  4. Affected versionversion=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <a99a617701186dc68c7b330d35fc2253f48e2ab2
  5. Affected versionversion=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <e3e59ff22a0de01ed0cf3a3e25558811abc3b70a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <5492799ec5d27be3bd454dcaf046bc7054f637ae; version=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <794a01110390c1b76f59ece773fb0fbfd89c6f5c; version=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <a99a617701186dc68c7b330d35fc2253f48e2ab2; version=8230fd8217b7ea76f838ae88e4a5a8e54f37099f <e3e59ff22a0de01ed0cf3a3e25558811abc3b70a

Published CVSS scores

7.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
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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