CVE-2025-21927: Linux kernel · nvme-tcp: fix potential memory corruption in nvme_tcp_recv_pdu()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 30 Oct 2026, 14:17 UTC
Contested
Scorers differ by 2 or more points| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|---|---|
| CISA-ADP | CVSS 3.1 | 7.8 |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel by rejecting packets with unexpected header lengths in nvme_tcp_recv_pdu(). Users and administrators should apply the official Linux kernel updates that include this fix to mitigate the risk.
Description
CVE-2025-21927 is a critical vulnerability in the Linux kernel's nvme-tcp driver where the function nvme_tcp_recv_pdu() does not validate the header length properly. This can lead to memory corruption when header digests are enabled, as a malicious target may send a packet with an invalid header length causing out-of-bounds memory access and overwriting memory with a calculated digest. The issue is fixed by rejecting packets with unexpected header lengths.
References
- git.kernel.org/stable/c/3b54109b2f771f74fd53b027429796326f84ab36 (opens in a new tab)
- git.kernel.org/stable/c/9d22cf5cc94cd7dee84773ec41db78a46107dfa3 (opens in a new tab)
- git.kernel.org/stable/c/9fbc953d6b38bc824392e01850f0aeee3b348722 (opens in a new tab)
- git.kernel.org/stable/c/22b06c89aa6b2d1ecb8aea72edfb9d53af8d5126 (opens in a new tab)
- git.kernel.org/stable/c/ad95bab0cd28ed77c2c0d0b6e76e03e031391064 (opens in a new tab)