High 8.8Published Apr 1, 2025

CVE-2025-21972net: mctp: unshare packets when reassembling

Updated under an hour ago (Oct 27, 2026, 2:30 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: net: mctp: unshare packets when reassembling Ensure that the frag_list used for reassembly isn't shared with other packets. This avoids incorrect reassembly when packets are cloned, and prevents a memory leak due to circular references between fragments and their skb_shared_info. The upcoming MCTP-over-USB driver uses skb_clone which can trigger the problem - other MCTP drivers don't share SKBs. A kunit test is added to reproduce the issue.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 21, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	4a992bbd365094730a31bae1e12a6ca695336d57 builds before 3d0281d0713952e8dd14d6d47e3a9c345c28a3b7; from 4a992bbd365094730a31bae1e12a6ca695336d57 before 5c47d5bfa7b096cf8890afac32141c578583f8e0; from 4a992bbd365094730a31bae1e12a6ca695336d57 before f44fff3d3c6cd67b6f348b821d73c4d6888c7a6e; from 4a992bbd365094730a31bae1e12a6ca695336d57 before f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc	CNA record
linux linux_kernel linux:linux_kernel	from 5.15 before 6.12.20; from 6.13 before 6.13.8; 6.14; 6.14; 6.14; 6.14; 6.14; 6.14	NVD

References

References

https://git.kernel.org/stable/c/3d0281d0713952e8dd14d6d47e3a9c345c28a3b7
https://git.kernel.org/stable/c/5c47d5bfa7b096cf8890afac32141c578583f8e0	patch
https://git.kernel.org/stable/c/f44fff3d3c6cd67b6f348b821d73c4d6888c7a6e	patch
https://git.kernel.org/stable/c/f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.