CVE-2025-21981: Linux kernel · ice: fix memory leak in aRFS after reset
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1086.93~20.04.1 : update Linux kernel when convenient.
Data as of 12 Nov 2026, 19:27 UTC
- Patch
- Available – fixed in 5.15.0-1086.93~20.04.1, 5.15.0-1091.100~20.04.1, 5.15.0-1085.94~20.04.1 +64
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 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7591-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7592-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7597-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7598-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7602-1 (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)
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.
AI-suggested
A patch is available and included in Linux kernel versions 5.15.0-1039.39~20.04.1 and later listed fixed versions. Users should update their Linux kernel to one of the fixed versions to remediate this memory leak vulnerability. After updating, a system reboot is required to apply the fixes. No additional mitigation actions are necessary.
Description
CVE-2025-21981 is a vulnerability in the Linux kernel's ice driver that causes a memory leak in the accelerated Receive Flow Steering (aRFS) structures after a reset. The issue occurs because memory allocated during VSI reconfiguration on reset is not properly released if it was previously allocated. This flaw has been fixed in multiple Linux kernel versions. The vulnerability has a medium severity score and does not affect confidentiality or integrity but impacts availability due to memory leakage.
References
- ubuntu.com/security/CVE-2025-21981 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21981 (opens in a new tab)
- git.kernel.org/linus/23d97f18901ef5e4e264e3b1777fe65c760186b5 (opens in a new tab)
- git.kernel.org/stable/c/23d97f18901ef5e4e264e3b1777fe65c760186b5 (opens in a new tab)
- git.kernel.org/stable/c/3b27e6e10a32589fcd293b8933ab6de9387a460e (opens in a new tab)
- git.kernel.org/stable/c/5d30d256661fc11b6e73fac6c3783a702e1006a3 (opens in a new tab)
- git.kernel.org/stable/c/78f3d64b30210c0e521c59357431aca14024cb79 (opens in a new tab)
- git.kernel.org/stable/c/fcbacc47d16306c87ad1b820b7a575f6e9eae58b (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7592-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7591-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7597-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7598-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7602-1 (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)