CVE-2026-23243

Kernel memory corruption via negative RDMA length

Published Mar 18, 2026 · Updated Mar 18, 2026

Out-of-bounds write in the Linux Kernel RDMA user-MAD component allows local users to corrupt kernel memory through a crafted write. ib_umad_write derives a negative data_len from inconsistent user MAD and RMPP header lengths, causing alloc_send_rmpp_list to overrun a slab buffer during padding. The path requires local low-privilege access to an RDMA umad device; successful corruption can crash the system or compromise kernel data.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the Linux Kernel RDMA user-MAD component allows local users to corrupt kernel memory through a crafted write. ib_umad_write derives a negative data_len from inconsistent user MAD and RMPP header lengths, causing alloc_send_rmpp_list to overrun a slab buffer during padding. The path requires local low-privilege access to an RDMA umad device; successful corruption can crash the system or compromise kernel data.

The record

CVE
CVE-2026-23243
Published
Mar 18, 2026
Updated
Mar 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 18, 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=2.6.24
  2. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <1371ef6b1ecf3676b8942f5dfb3634fb0648128e
  3. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <205955f29c26330b1dc7fdeadd5bb97c38e26f56
  4. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <362e45fd9069ffa1523f9f1633b606ebf72060d7
  5. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b
  6. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <5551b02fdbfd85a325bb857f3a8f9c9f33397ed2
  7. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <6eb2919474ca105c5b13d19574e25f0ddcf19ca2
  8. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <9c80d688f402539dfc8f336de1380d6b4ee14316
  9. Affected versionversion=2be8e3ee8efd6f99ce454115c29d09750915021a <a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.24; version=2be8e3ee8efd6f99ce454115c29d09750915021a <1371ef6b1ecf3676b8942f5dfb3634fb0648128e; version=2be8e3ee8efd6f99ce454115c29d09750915021a <205955f29c26330b1dc7fdeadd5bb97c38e26f56; version=2be8e3ee8efd6f99ce454115c29d09750915021a <362e45fd9069ffa1523f9f1633b606ebf72060d7; version=2be8e3ee8efd6f99ce454115c29d09750915021a <52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b; version=2be8e3ee8efd6f99ce454115c29d09750915021a <5551b02fdbfd85a325bb857f3a8f9c9f33397ed2; version=2be8e3ee8efd6f99ce454115c29d09750915021a <6eb2919474ca105c5b13d19574e25f0ddcf19ca2; version=2be8e3ee8efd6f99ce454115c29d09750915021a <9c80d688f402539dfc8f336de1380d6b4ee14316; version=2be8e3ee8efd6f99ce454115c29d09750915021a <a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d

Published CVSS scores

7.8kernel.orgCVSS: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 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

CWE-787Out-of-bounds Write

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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