CVE-2026-53398Network attack vector

Remote kernel code execution via stale export pointer

Published Jul 19, 2026 · Updated Jul 19, 2026

Use-after-free in Linux Kernel NFSD allows remote attackers to execute kernel code through crafted NFSv4 COMPOUND RPC requests. The nfsd4_decode_secinfo_no_name() decoder leaves sin_exp uninitialized when truncated XDR fails after sin_style decoding, and cleanup passes stale union contents to exp_put(). Network reachability to an active NFSv4.1 server is sufficient; the resulting export-cache corruption enables kernel memory disclosure, kernel code execution, or a kernel crash.

CVSS severity9.8
Critical
EPSS probability0.54%
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 NFSD allows remote attackers to execute kernel code through crafted NFSv4 COMPOUND RPC requests. The nfsd4_decode_secinfo_no_name() decoder leaves sin_exp uninitialized when truncated XDR fails after sin_style decoding, and cleanup passes stale union contents to exp_put(). Network reachability to an active NFSv4.1 server is sufficient; the resulting export-cache corruption enables kernel memory disclosure, kernel code execution, or a kernel crash.

The record

CVE
CVE-2026-53398
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

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=07b68ff5c71cf4ed5443016d8eb116863c0a4d88 <49de5d31dd8fdebf78bdeaf196b0ca5cd5c75439
  2. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <161d1aaeb04d620d3692639700512bb5038c1e10
  3. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <1e04be34cafae119e82bcaccd6d28a20f72a3647
  4. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <46eb17d45be69d28c7a23ea03283b207426a8232
  5. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <5ec37edcb534f3fc92304be236d37f08e6545585
  6. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <9e18e83b8846a5c3fe13fc8a464b4865d33996c6
  7. Affected versionversion=3fdc546462348b8a497c72bc894e0cde9f10fc40 <c8a24effd96d4779e2ad779654682304491c55a5
  8. Affected versionversion=5.10.220 <5.10.260
  9. Affected versionversion=5.15.154 <5.15.211
  10. Affected versionversion=5e76b25d7cc82c148d391c0c43b884e6427cb302 <8836405abdc53ca3dd5fc68b2cf6f8f012fad011
  11. Affected versionversion=6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=07b68ff5c71cf4ed5443016d8eb116863c0a4d88 <49de5d31dd8fdebf78bdeaf196b0ca5cd5c75439; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <161d1aaeb04d620d3692639700512bb5038c1e10; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <1e04be34cafae119e82bcaccd6d28a20f72a3647; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <46eb17d45be69d28c7a23ea03283b207426a8232; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <5ec37edcb534f3fc92304be236d37f08e6545585; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <9e18e83b8846a5c3fe13fc8a464b4865d33996c6; version=3fdc546462348b8a497c72bc894e0cde9f10fc40 <c8a24effd96d4779e2ad779654682304491c55a5; version=5.10.220 <5.10.260; version=5.15.154 <5.15.211; version=5e76b25d7cc82c148d391c0c43b884e6427cb302 <8836405abdc53ca3dd5fc68b2cf6f8f012fad011; version=6.1

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

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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