CVE-2023-53525

Service interruption via uninitialized RDMA qkey read

Published Oct 1, 2025 · Updated May 23, 2026

Use of uninitialized memory in Linux kernel RDMA/CMA allows local users to interrupt service via a crafted UCMA multicast join. cma_iboe_join_multicast leaves ib->rec.qkey uninitialized for some UD-compatible port spaces, and cma_set_qkey later reads it while constructing the multicast event. Low-privileged local access to UCMA is required; the published assessment reports availability impact without confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized memory in Linux kernel RDMA/CMA allows local users to interrupt service via a crafted UCMA multicast join. cma_iboe_join_multicast leaves ib->rec.qkey uninitialized for some UD-compatible port spaces, and cma_set_qkey later reads it while constructing the multicast event. Low-privileged local access to UCMA is required; the published assessment reports availability impact without confidentiality or integrity impact.

The record

CVE
CVE-2023-53525
Published
Oct 1, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=5.10
  2. Affected versionversion=5.8.17 <5.9
  3. Affected versionversion=5.9.2 <5.10
  4. Affected versionversion=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <02eabb635bc64bd1e3a7cf887d6d182bffb64b99
  5. Affected versionversion=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <48e8e7851dc0b1584d83817a78fc7108c8904b54
  6. Affected versionversion=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <58e84f6b3e84e46524b7e5a916b53c1ad798bc8f
  7. Affected versionversion=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <ae11498851423d6de27aebfe12a5ee85060ab1d5
  8. Affected versionversion=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <bb18b9dbac2bbdf7695e0bfaac4bf944ff7b207d
  9. Affected versionversion=b8d1adbff983be0b54f61c9a4169609d7fab0620
  10. Affected versionversion=feed39c8d1282279fcb30612aa0e8d2635c11280

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=5.8.17 <5.9; version=5.9.2 <5.10; version=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <02eabb635bc64bd1e3a7cf887d6d182bffb64b99; version=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <48e8e7851dc0b1584d83817a78fc7108c8904b54; version=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <58e84f6b3e84e46524b7e5a916b53c1ad798bc8f; version=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <ae11498851423d6de27aebfe12a5ee85060ab1d5; version=b5de0c60cc30c2a3513c7188c73f3f29acc29234 <bb18b9dbac2bbdf7695e0bfaac4bf944ff7b207d; version=b8d1adbff983be0b54f61c9a4169609d7fab0620; version=feed39c8d1282279fcb30612aa0e8d2635c11280

Published CVSS scores

5.5CanonicalCVSS: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

T1499Endpoint Denial of Service

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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