CVE-2026-31533Network attack vector

Unauthenticated kernel memory corruption via duplicate cleanup

Published Apr 23, 2026 · Updated Apr 23, 2026

Use-after-free in Linux Kernel net/tls allows remote attackers to corrupt kernel memory through a kTLS-enabled network service. When crypto_aead_encrypt() returns -EBUSY, tls_encrypt_done() and tls_do_encryption() both restore the scatterlist and decrement encrypt_pending, corrupting its sentinel. The service must use the kTLS transmit path; a later sendmsg can free tls_rec before the pending callback fires, causing stale kernel-memory access and a crash.

CVSS severity9.8
Critical
EPSS probability0.39%
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 net/tls allows remote attackers to corrupt kernel memory through a kTLS-enabled network service. When crypto_aead_encrypt() returns -EBUSY, tls_encrypt_done() and tls_do_encryption() both restore the scatterlist and decrement encrypt_pending, corrupting its sentinel. The service must use the kTLS transmit path; a later sendmsg can free tls_rec before the pending callback fires, causing stale kernel-memory access and a crash.

The record

CVE
CVE-2026-31533
Published
Apr 23, 2026
Updated
Apr 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=13eca403876bbea3716e82cdfe6f1e6febb38754 <0e43e0a3c94044acc74b8e0927c27972eb5a59e8
  2. Affected versionversion=3ade391adc584f17b5570fd205de3ad029090368 <414fc5e5a5aff776c150f1b86770e0a25a35df3a
  3. Affected versionversion=6.8
  4. Affected versionversion=8590541473188741055d27b955db0777569438e3 <2694d408b0e595024e0fc1d64ff9db0358580f74
  5. Affected versionversion=8590541473188741055d27b955db0777569438e3 <5d70eb25b41e9b010828cd12818b06a0c3b04412
  6. Affected versionversion=8590541473188741055d27b955db0777569438e3 <a9b8b18364fffce4c451e6f6fd218fa4ab646705
  7. Affected versionversion=8590541473188741055d27b955db0777569438e3 <aa9facde6c5005205874c37db3fd25799d741baf
  8. Affected versionversion=ab6397f072e5097f267abf5cb08a8004e6b17694
  9. Affected versionversion=cd1bbca03f3c1d845ce274c0d0a66de8e5929f72 <02f3ecadb23558bbe068e6504118f1b712d4ece0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=13eca403876bbea3716e82cdfe6f1e6febb38754 <0e43e0a3c94044acc74b8e0927c27972eb5a59e8; version=3ade391adc584f17b5570fd205de3ad029090368 <414fc5e5a5aff776c150f1b86770e0a25a35df3a; version=6.8; version=8590541473188741055d27b955db0777569438e3 <2694d408b0e595024e0fc1d64ff9db0358580f74; version=8590541473188741055d27b955db0777569438e3 <5d70eb25b41e9b010828cd12818b06a0c3b04412; version=8590541473188741055d27b955db0777569438e3 <a9b8b18364fffce4c451e6f6fd218fa4ab646705; version=8590541473188741055d27b955db0777569438e3 <aa9facde6c5005205874c37db3fd25799d741baf; version=ab6397f072e5097f267abf5cb08a8004e6b17694; version=cd1bbca03f3c1d845ce274c0d0a66de8e5929f72 <02f3ecadb23558bbe068e6504118f1b712d4ece0

Published CVSS scores

9.8kernel.orgCVSS: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 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

CWE-416Use After Free
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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