CVE-2025-21927 nvme-tcp: fix potential memory corruption in nvme_tcp_recv_pdu()

What is CVE-2025-21927?

CVE-2025-21927 is a critical memory corruption vulnerability in Linux kernel, published on 1 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-787

Which versions are affected by CVE-2025-21927?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21927?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-21927 being exploited?

There is no known exploitation of CVE-2025-21927 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-59922, AZL-59952, BELL-CVE-2025-21927, DEBIAN-CVE-2025-21927, GHSA-p4qc-cp8p-44wh, RHSA-2025:4339 and 13 more.