CVE-2025-40337
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Correctly handle Rx checksum offload errors The stmmac_rx function would previously set skb->ip_summed to CHECKSUM_UNNECESSARY if hardware checksum offload (CoE) was enabled and the packet was of a known IP ethertype. However, this logic failed to check if the hardware had actually reported a checksum error. The hardware status, indicating a header or payload checksum failure, was being ignored at this stage. This could cause corrupt packets to be passed up the network stack as valid. This patch corrects the logic by checking the `csum_none` status flag, which is set when the hardware reports a checksum error. If this flag is set, skb->ip_summed is now correctly set to CHECKSUM_NONE, ensuring the kernel's network stack will perform its own validation and properly handle the corrupt packet.
Affected versions
Linux kernel versions
3.2
and later are affected. Fixed in
6.6.117,
6.12.58,
6.17.8,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40337 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/1aa319e0f12d2d761a31556b82a5852c98eb0bea
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PatchKernel patch commithttps://git.kernel.org/stable/c/63fbe0e6413279d5ea5842e2423e351ded547683
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PatchKernel patch commithttps://git.kernel.org/stable/c/719fcdf29051f7471d5d433475af76219019d33d
Frequently asked questions
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What is CVE-2025-40337?
CVE-2025-40337 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 3.2 onward and has been patched in 6.6.117, 6.12.58, 6.17.8 and others. CVE-2025-40337 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-2025-40337?
Yes — CVE-2025-40337 has been patched. Fixed versions include 6.6.117, 6.12.58, 6.17.8 and others. If you are running Linux kernel 3.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40337 actively exploited?
No — CVE-2025-40337 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.