CVE-2026-23399
MediumIn the Linux kernel, the following vulnerability has been resolved: nf_tables: nft_dynset: fix possible stateful expression memleak in error path If cloning the second stateful expression in the element via GFP_ATOMIC fails, then the first stateful expression remains in place without being released. unreferenced object (percpu) 0x607b97e9cab8 (size 16): comm "softirq", pid 0, jiffies 4294931867 hex dump (first 16 bytes on cpu 3): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 backtrace (crc 0): pcpu_alloc_noprof+0x453/0xd80 nft_counter_clone+0x9c/0x190 [nf_tables] nft_expr_clone+0x8f/0x1b0 [nf_tables] nft_dynset_new+0x2cb/0x5f0 [nf_tables] nft_rhash_update+0x236/0x11c0 [nf_tables] nft_dynset_eval+0x11f/0x670 [nf_tables] nft_do_chain+0x253/0x1700 [nf_tables] nft_do_chain_ipv4+0x18d/0x270 [nf_tables] nf_hook_slow+0xaa/0x1e0 ip_local_deliver+0x209/0x330
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-401CVE-2026-23399 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.11
and later are affected. Fixed in
5.15.209,
6.1.175,
6.6.136,
6.12.78,
6.18.20,
6.19.10,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-23399 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/0548a13b5a145b16e4da0628b5936baf35f51b43
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PatchKernel patch commithttps://git.kernel.org/stable/c/31641c682db73353e4647e40735c7f2a75ff58ef
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PatchKernel patch commithttps://git.kernel.org/stable/c/4357dbb1d9c35ca0b4443d71c98a48e6666f7689
Frequently asked questions
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What is CVE-2026-23399?
CVE-2026-23399 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.11 onward and has been patched in 5.15.209, 6.1.175, 6.6.136 and others. CVE-2026-23399 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-2026-23399?
CVE-2026-23399 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-2026-23399?
Yes — CVE-2026-23399 has been patched. Fixed versions include 5.15.209, 6.1.175, 6.6.136 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-23399 actively exploited?
No — CVE-2026-23399 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 Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →