CVE-2023-53108

Kernel crash via undersized IUCV interrupt buffer

Published May 2, 2025 · Updated May 11, 2026

An out-of-bounds write in Linux IUCV before 6.3 allows local users to crash the kernel when a z/VM virtual CPU is deconfigured. The iucv_cpu_prepare path allocates iucv_irq_data four bytes too short, so the hypervisor's CPU-deconfiguration interrupt writes past the kmalloc object into its redzone. Exploitation requires an s390 Linux guest under z/VM, IUCV initialization, and the ability to trigger CPU deconfiguration; the documented impact is a kernel crash without data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in Linux IUCV before 6.3 allows local users to crash the kernel when a z/VM virtual CPU is deconfigured. The iucv_cpu_prepare path allocates iucv_irq_data four bytes too short, so the hypervisor's CPU-deconfiguration interrupt writes past the kmalloc object into its redzone. Exploitation requires an s390 Linux guest under z/VM, IUCV initialization, and the ability to trigger CPU deconfiguration; the documented impact is a kernel crash without data disclosure or modification.

The record

CVE
CVE-2023-53108
Published
May 2, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 2, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=2356f4cb191100a5e92d537f13e5efdbc697e9cb <3cfdefdaaa4b2a77e84d0db5e0a47a7aa3bb615a
  2. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <3d87debb8ed2649608ff432699e7c961c0c6f03b
  3. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <71da5991b6438ad6da13ceb25465ee2760a1c52f
  4. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <93a970494881004c348d8feb38463ee72496e99a
  5. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <a908eae0f71811afee86be7088692f1aa5855c3b
  6. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <b0d2bb5e31a693ebc8888eb407f8a257a3680efa
  7. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <bd2e78462ae18484e55ae4d285df2c86b86bdd12
  8. Affected versionversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <c78f1345db4e4b3b78f9b768f4074ebd60abe966
  9. Affected versionversion=2.6.21

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2356f4cb191100a5e92d537f13e5efdbc697e9cb <3cfdefdaaa4b2a77e84d0db5e0a47a7aa3bb615a; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <3d87debb8ed2649608ff432699e7c961c0c6f03b; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <71da5991b6438ad6da13ceb25465ee2760a1c52f; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <93a970494881004c348d8feb38463ee72496e99a; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <a908eae0f71811afee86be7088692f1aa5855c3b; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <b0d2bb5e31a693ebc8888eb407f8a257a3680efa; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <bd2e78462ae18484e55ae4d285df2c86b86bdd12; version=2356f4cb191100a5e92d537f13e5efdbc697e9cb <c78f1345db4e4b3b78f9b768f4074ebd60abe966; version=2.6.21

Published CVSS scores

5.5NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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