CVE-2024-26957

Local privilege escalation via zcrypt card use-after-free

Published May 1, 2024 · Updated Aug 5, 2026

Use-after-free in Linux s390 zcrypt allows local users to corrupt kernel memory through z90crypt ioctls during crypto-card removal. Incorrect reference handling lets zcrypt_card_put free a struct zcrypt_card while zcrypt_pick_queue users still access its load and limit fields. A local unprivileged user with access to /dev/z90crypt can force the removal path, producing kernel reads and writes that support privilege escalation or a crash.

CVSS severity7.8
High
EPSS probability0.24%
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 s390 zcrypt allows local users to corrupt kernel memory through z90crypt ioctls during crypto-card removal. Incorrect reference handling lets zcrypt_card_put free a struct zcrypt_card while zcrypt_pick_queue users still access its load and limit fields. A local unprivileged user with access to /dev/z90crypt can force the removal path, producing kernel reads and writes that support privilege escalation or a crash.

The record

CVE
CVE-2024-26957
Published
May 1, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 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

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=4.10
  2. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484
  3. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <50ed48c80fecbe17218afed4f8bed005c802976c
  4. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <6470078ab3d8f222115e11c4ec67351f3031b3dd
  5. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <7e500849fa558879a1cde43f80c7c048c2437058
  6. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <9daddee03de3f231012014dab8ab2b277a116a55
  7. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <a55677878b93e9ebc31f66d0e2fb93be5e7836a6
  8. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <a64ab862e84e3e698cd351a87cdb504c7fc575ca
  9. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <b7f6c3630eb3f103115ab0d7613588064f665d0d
  10. Affected versionversion=e28d2af43614eb86f59812e7221735fc221bbc10 <befb7f889594d23e1b475720cf93efd2f77df000

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.10; version=e28d2af43614eb86f59812e7221735fc221bbc10 <394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484; version=e28d2af43614eb86f59812e7221735fc221bbc10 <50ed48c80fecbe17218afed4f8bed005c802976c; version=e28d2af43614eb86f59812e7221735fc221bbc10 <6470078ab3d8f222115e11c4ec67351f3031b3dd; version=e28d2af43614eb86f59812e7221735fc221bbc10 <7e500849fa558879a1cde43f80c7c048c2437058; version=e28d2af43614eb86f59812e7221735fc221bbc10 <9daddee03de3f231012014dab8ab2b277a116a55; version=e28d2af43614eb86f59812e7221735fc221bbc10 <a55677878b93e9ebc31f66d0e2fb93be5e7836a6; version=e28d2af43614eb86f59812e7221735fc221bbc10 <a64ab862e84e3e698cd351a87cdb504c7fc575ca; version=e28d2af43614eb86f59812e7221735fc221bbc10 <b7f6c3630eb3f103115ab0d7613588064f665d0d; version=e28d2af43614eb86f59812e7221735fc221bbc10 <befb7f889594d23e1b475720cf93efd2f77df000
The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f4 <394b6d8bbdf9; version=1da177e4c3f4 <50ed48c80fec; version=1da177e4c3f4 <6470078ab3d8; version=1da177e4c3f4 <7e500849fa55; version=1da177e4c3f4 <9daddee03de3; version=1da177e4c3f4 <a55677878b93; version=1da177e4c3f4 <a64ab862e84e; version=1da177e4c3f4 <b7f6c3630eb3; version=1da177e4c3f4 <befb7f889594

Published CVSS scores

7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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