Buffer overflow in Linux

CVE-2025-21927

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix potential memory corruption in nvme_tcp_recv_pdu() nvme_tcp_recv_pdu() doesn't check the validity of the header length. When header digests are enabled, a target might send a packet with an invalid header length (e.g. 255), causing nvme_tcp_verify_hdgst() to access memory outside the allocated area and cause memory corruptions by overwriting it with the calculated digest. Fix this by rejecting packets with an unexpected header length.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (11.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21927?
CVE-2025-21927 is a critical-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2025-04-01.
How severe is CVE-2025-21927?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-21927 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.