CVE-2025-38550

Local privilege escalation via multicast use-after-free

Published Aug 16, 2025 · Updated Aug 5, 2026

Use-after-free in the Linux kernel's IPv6 multicast code allows local users to gain kernel privileges through socket calls. mld_del_delrec() drops the pmc->idev reference before ip6_mc_clear_src() finishes using that refcounted network object. An unprivileged process can trigger the path by joining, dropping, and rejoining a multicast group, enabling kernel-memory access or a kernel panic.

CVSS severity7.8
High
EPSS probability0.16%
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 the Linux kernel's IPv6 multicast code allows local users to gain kernel privileges through socket calls. mld_del_delrec() drops the pmc->idev reference before ip6_mc_clear_src() finishes using that refcounted network object. An unprivileged process can trigger the path by joining, dropping, and rejoining a multicast group, enabling kernel-memory access or a kernel panic.

The record

CVE
CVE-2025-38550
Published
Aug 16, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 16, 2025CVE 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

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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=5.13
  2. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <5f18e0130194550dff734e155029ae734378b5ea
  3. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <6e4eec86fe5f6b3fdbc702d1d36ac2a6e7ec0806
  4. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <728db00a14cacb37f36e9382ab5fad55caf890cc
  5. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <7929d27c747eafe8fca3eecd74a334503ee4c839
  6. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <ae3264a25a4635531264728859dbe9c659fad554
  7. Affected versionversion=63ed8de4be81b699ca727e9f8e3344bd487806d7 <dcbc346f50a009d8b7f4e330f9f2e22d6442fa26
  8. Affected versionversion=b564ec4491d24b40900c64ab9e29a208f17f3108 <1b5b413094af8d88a31b5df3fd262f6baca53841

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <5f18e0130194550dff734e155029ae734378b5ea; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <6e4eec86fe5f6b3fdbc702d1d36ac2a6e7ec0806; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <728db00a14cacb37f36e9382ab5fad55caf890cc; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <7929d27c747eafe8fca3eecd74a334503ee4c839; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <ae3264a25a4635531264728859dbe9c659fad554; version=63ed8de4be81b699ca727e9f8e3344bd487806d7 <dcbc346f50a009d8b7f4e330f9f2e22d6442fa26; version=b564ec4491d24b40900c64ab9e29a208f17f3108 <1b5b413094af8d88a31b5df3fd262f6baca53841

Published CVSS scores

7.3UbuntuCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS: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

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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