CVE-2024-53217

Host crash via missing NFSD backchannel session

Published Dec 27, 2024 · Updated Aug 5, 2026

NULL pointer dereference in Linux kernel NFSD allows local users to crash the host through an NFSv4 callback update. When __nfsd4_find_backchannel() returns no available backchannel session, nfsd4_process_cb_update() leaves ses NULL but passes it to setup_callback_client(), which dereferences it. A low-privileged local user must reach the NFSD callback-update path; the published impact is a kernel crash, with no confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.70%
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 Linux kernel NFSD allows local users to crash the host through an NFSv4 callback update. When __nfsd4_find_backchannel() returns no available backchannel session, nfsd4_process_cb_update() leaves ses NULL but passes it to setup_callback_client(), which dereferences it. A low-privileged local user must reach the NFSD callback-update path; the published impact is a kernel crash, with no confidentiality or integrity impact.

The record

CVE
CVE-2024-53217
Published
Dec 27, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=2.6.38
  2. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <03178cd8f67227015debb700123987fe96275cd1
  3. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <0c3b0e326f838787d229314d4de83af9c53347e8
  4. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <1e02c641c3a43c88cecc08402000418e15578d38
  5. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <4a4ffc1aa9d618e41ad9151f40966e402e58a5a2
  6. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <752a75811f27300fe8131b0a1efc91960f6f88e7
  7. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <c5d90f9302742985a5078e42ac38de42c364c44a
  8. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <cac1405e3ff6685a438e910ad719e0cf06af90ee
  9. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <d9a0d1f6e15859ea7a86a327f28491e23deaaa62
  10. Affected versionversion=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <eb51733ae5fc73d95bd857d5da26f9f65b202a79

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.38; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <03178cd8f67227015debb700123987fe96275cd1; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <0c3b0e326f838787d229314d4de83af9c53347e8; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <1e02c641c3a43c88cecc08402000418e15578d38; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <4a4ffc1aa9d618e41ad9151f40966e402e58a5a2; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <752a75811f27300fe8131b0a1efc91960f6f88e7; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <c5d90f9302742985a5078e42ac38de42c364c44a; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <cac1405e3ff6685a438e910ad719e0cf06af90ee; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <d9a0d1f6e15859ea7a86a327f28491e23deaaa62; version=dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 <eb51733ae5fc73d95bd857d5da26f9f65b202a79

Published CVSS scores

5.5CISA ADPCVSS: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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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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