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 · fixed in 6.8.0-1039.41~22.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1039.41~22.04.1, 6.8.0-1036.42~22.04.1, 6.8.0-1040.42~22.04.1 +34
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
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2025-21927 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21927 (opens in a new tab)
- git.kernel.org/linus/ad95bab0cd28ed77c2c0d0b6e76e03e031391064 (opens in a new tab)
- git.kernel.org/stable/c/22b06c89aa6b2d1ecb8aea72edfb9d53af8d5126 (opens in a new tab)
- git.kernel.org/stable/c/9fbc953d6b38bc824392e01850f0aeee3b348722 (opens in a new tab)
- git.kernel.org/stable/c/ad95bab0cd28ed77c2c0d0b6e76e03e031391064 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7628-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7764-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7765-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7779-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7764-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7790-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-1 (opens in a new tab)