CVE-2025-21954: Linux kernel · netmem: prevent TX of unreadable skbs
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 29 Oct 2026, 23:32 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 29 Oct 2026.
What to do
AI-suggested
A fix is available in the Linux kernel that prevents transmission of unreadable skbs. Users should update to the fixed kernel versions once released. No additional mitigations are indicated by the vendor advisory.
Description
CVE-2025-21954 is a vulnerability in the Linux kernel's netmem subsystem where unreadable socket buffers (skbs) could be transmitted (TX) improperly. This flaw could cause the device driver to call DMA mapping APIs on invalid DMA addresses, potentially leading to a denial of service. The issue has been fixed by preventing transmission of unreadable skbs, ensuring safer handling of redirected packets.
References
- nvd.nist.gov/vuln/detail/CVE-2025-21954 (opens in a new tab)
- git.kernel.org/stable/c/1c17c8ced25c5fbe424c7ad7ea11d33014a986b1 (opens in a new tab)
- git.kernel.org/stable/c/454825019d2f0c59e5174ece9e713f45ad80beff (opens in a new tab)
- git.kernel.org/stable/c/f3600c867c99a2cc8038680ecf211089c50e7971 (opens in a new tab)