CVE-2026-43493Network attack vector

Kernel memory corruption via mishandled backlog completion

Published May 19, 2026 · Updated May 19, 2026

Use-after-free in the Linux Kernel pcrypt path allows remote attackers to corrupt kernel memory through concurrent crypto requests. pcrypt treats a child request's EBUSY backlog result as terminal, completes and frees the parent request, then accepts a later callback into freed state. Reachability requires an affected pcrypt AEAD consumer such as kTLS or TIPC; induced queue pressure can cause disclosure, arbitrary writes, or a kernel panic.

CVSS severity9.8
Critical
EPSS probability0.55%
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 the Linux Kernel pcrypt path allows remote attackers to corrupt kernel memory through concurrent crypto requests. pcrypt treats a child request's EBUSY backlog result as terminal, completes and frees the parent request, then accepts a later callback into freed state. Reachability requires an affected pcrypt AEAD consumer such as kTLS or TIPC; induced queue pressure can cause disclosure, arbitrary writes, or a kernel panic.

The record

CVE
CVE-2026-43493
Published
May 19, 2026
Updated
May 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 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=2.6.34
  2. Affected versionversion=5a1436beec5744029f3ac90b6fe71a698dcd6155 <46271895ddfb1ba41f89f7e0dffbe9c2bcf7380a
  3. Affected versionversion=5a1436beec5744029f3ac90b6fe71a698dcd6155 <77d55bc8675ee851ed639dc9be77325a8024cf67
  4. Affected versionversion=5a1436beec5744029f3ac90b6fe71a698dcd6155 <915b692e6cb723aac658c25eb82c58fd81235110
  5. Affected versionversion=5a1436beec5744029f3ac90b6fe71a698dcd6155 <9f1cbca178c03188e201ed175251372149bb25f2
  6. Affected versionversion=5a1436beec5744029f3ac90b6fe71a698dcd6155 <eb34e243df57e32f4c08fa191f3602ea19076276

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.34; version=5a1436beec5744029f3ac90b6fe71a698dcd6155 <46271895ddfb1ba41f89f7e0dffbe9c2bcf7380a; version=5a1436beec5744029f3ac90b6fe71a698dcd6155 <77d55bc8675ee851ed639dc9be77325a8024cf67; version=5a1436beec5744029f3ac90b6fe71a698dcd6155 <915b692e6cb723aac658c25eb82c58fd81235110; version=5a1436beec5744029f3ac90b6fe71a698dcd6155 <9f1cbca178c03188e201ed175251372149bb25f2; version=5a1436beec5744029f3ac90b6fe71a698dcd6155 <eb34e243df57e32f4c08fa191f3602ea19076276

Published CVSS scores

9.8UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8Linux kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.3UbuntuCVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.0Oracle LinuxCVSS:3.1/AV:L/AC:H/PR:L/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

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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