CVE-2026-23103
MediumIn the Linux kernel, the following vulnerability has been resolved: ipvlan: Make the addrs_lock be per port Make the addrs_lock be per port, not per ipvlan dev. Initial code seems to be written in the assumption, that any address change must occur under RTNL. But it is not so for the case of IPv6. So 1) Introduce per-port addrs_lock. 2) It was needed to fix places where it was forgotten to take lock (ipvlan_open/ipvlan_close) This appears to be a very minor problem though. Since it's highly unlikely that ipvlan_add_addr() will be called on 2 CPU simultaneously. But nevertheless, this could cause: 1) False-negative of ipvlan_addr_busy(): one interface iterated through all port->ipvlans + ipvlan->addrs under some ipvlan spinlock, and another added IP under its own lock. Though this is only possible for IPv6, since looks like only ipvlan_addr6_event() can be called without rtnl_lock. 2) Race since ipvlan_ht_addr_add(port) is called under different ipvlan->addrs_lock locks This should not affect performance, since add/remove IP is a rare situation and spinlock is not taken on fast paths.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-667CVE-2026-23103 is a Improper Locking vulnerability
What is Improper Locking?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE
Affected versions
Linux kernel versions
4.17
and later are affected. Fixed in
5.10.249,
5.15.199,
6.1.162,
6.6.122,
6.12.68,
6.18.8,
6.19
and their respective stable series.
References
The following references provide additional information about CVE-2026-23103 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/04ba6de6eff61238e5397c14ac26a6578c7735a5
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PatchKernel patch commithttps://git.kernel.org/stable/c/1f300c10d92c547c3a7d978e1212ff52f18256ed
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PatchKernel patch commithttps://git.kernel.org/stable/c/3c149b662cbb202a450e81f938e702ba333864ad
Frequently asked questions
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What is CVE-2026-23103?
CVE-2026-23103 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 4.17 onward and has been patched in 5.10.249, 5.15.199, 6.1.162 and others. CVE-2026-23103 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-23103?
CVE-2026-23103 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-23103?
Yes — CVE-2026-23103 has been patched. Fixed versions include 5.10.249, 5.15.199, 6.1.162 and others. If you are running Linux kernel 4.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-23103 actively exploited?
No — CVE-2026-23103 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Improper Locking (CWE-667)?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →