CVE-2026-98360

Local use-after-free via premature multicast-group publication

Published Oct 6, 2026 · Updated Oct 6, 2026

Use-after-free in Linux kernel RDMA/rxe allows local users to trigger a stale multicast-group lookup through a userspace RDMA client. The rxe_get_mcg() error path frees a group after publishing it in mcg_tree when rxe_mcast_add() fails, leaving __rxe_lookup_mcg() to dereference freed memory on the next lookup. Access to the rxe uverbs device and a UD queue pair is required, as is a failed multicast-address add; the demonstrated outcome is a KASAN-detected kernel use-after-free.

CVSS severityUnavailable
Unscored
EPSS probability0.13%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel RDMA/rxe allows local users to trigger a stale multicast-group lookup through a userspace RDMA client. The rxe_get_mcg() error path frees a group after publishing it in mcg_tree when rxe_mcast_add() fails, leaving __rxe_lookup_mcg() to dereference freed memory on the next lookup. Access to the rxe uverbs device and a UD queue pair is required, as is a failed multicast-address add; the demonstrated outcome is a KASAN-detected kernel use-after-free.

The record

CVE
CVE-2026-98360
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=5.18
  2. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <02c0a2fa69c16248a7432af8a6d64ab2a73a5283
  3. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <1caceeb2d74bbe88223aea55eb8626b4c5f076fd
  4. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <c79a789aa15180a1543b5db49c343d12e3ec214d
  5. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <d4fc4e37f8a143b0fe83b42c8fb48cf542154fee
  6. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <ddb43ac0926d4a931bc9b7744b93627f627457e5
  7. Affected versionversion=a926a903b7dc39a8a949150258c09290998dd812 <faae1fb4ccf8205806a8802c008798dabeb0205b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.18; version=a926a903b7dc39a8a949150258c09290998dd812 <02c0a2fa69c16248a7432af8a6d64ab2a73a5283; version=a926a903b7dc39a8a949150258c09290998dd812 <1caceeb2d74bbe88223aea55eb8626b4c5f076fd; version=a926a903b7dc39a8a949150258c09290998dd812 <c79a789aa15180a1543b5db49c343d12e3ec214d; version=a926a903b7dc39a8a949150258c09290998dd812 <d4fc4e37f8a143b0fe83b42c8fb48cf542154fee; version=a926a903b7dc39a8a949150258c09290998dd812 <ddb43ac0926d4a931bc9b7744b93627f627457e5; version=a926a903b7dc39a8a949150258c09290998dd812 <faae1fb4ccf8205806a8802c008798dabeb0205b

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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