CVE-2026-45940
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix oops when split header is enabled For GMAC4, when split header is enabled, in some rare cases, the hardware does not fill buf2 of the first descriptor with payload. Thus we cannot assume buf2 is always fully filled if it is not the last descriptor. Otherwise, the length of buf2 of the second descriptor will be calculated wrong and cause an oops: Unable to handle kernel paging request at virtual address ffff00019246bfc0 ... x2 : 0000000000000040 x1 : ffff00019246bfc0 x0 : ffff00009246c000 Call trace: dcache_inval_poc+0x28/0x58 (P) dma_direct_sync_single_for_cpu+0x38/0x6c __dma_sync_single_for_cpu+0x34/0x6c stmmac_napi_poll_rx+0x8f0/0xb60 __napi_poll.constprop.0+0x30/0x144 net_rx_action+0x160/0x274 handle_softirqs+0x1b8/0x1fc ... To fix this, the PL bit-field in RDES3 register is used for all descriptors, whether it is the last descriptor or not.
Affected versions
Linux kernel versions
5.4
and later are affected. Fixed in
6.18.14,
6.19.4,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-45940 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/36f81cb7d82e9614a7058da6abdf2e3a03993df1
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PatchKernel patch commithttps://git.kernel.org/stable/c/b1f23df09e7dbf4c86b6908dff7efb8cb2b7d609
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PatchKernel patch commithttps://git.kernel.org/stable/c/babab1b42ed68877ef669a08384becf281ad2582
Frequently asked questions
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What is CVE-2026-45940?
CVE-2026-45940 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.4 onward and has been patched in 6.18.14, 6.19.4 and 7.0. CVE-2026-45940 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-45940?
Yes — CVE-2026-45940 has been patched. Fixed versions include 6.18.14, 6.19.4 and 7.0. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-45940 actively exploited?
No — CVE-2026-45940 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.