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CVE intelligence

CVE-2025-21981

Vulnerability intelligence

Published Apr 1, 2025Sources checked Oct 9, 2026
5.5MEDIUMCVSS out of 10
What this means

Review the available evidence

CVE-2025-21981 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Aug 12, 2026

CBL-Mariner Releases

Vendor-listed releases

  • 5.15.180.1-1
  • 6.6.85.1-2
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview

What is CVE-2025-21981?

In the Linux kernel, the following vulnerability has been resolved:

ice: fix memory leak in aRFS after reset

Fix aRFS (accelerated Receive Flow Steering) structures memory leak by adding a checker to verify if aRFS memory is already allocated while configuring VSI. aRFS objects are allocated in two cases: - as part of VSI initialization (at probe), and - as part of reset handling

However, VSI reconfiguration executed during reset involves memory allocation one more time, without prior releasing already allocated resources. This led to the memory leak with the following signature:

[root@os-delivery ~]# cat /sys/kernel/debug/kmemleak unreferenced object 0xff3c1ca7252e6000 (size 8192): comm "kworker/0:0", pid 8, jiffies 4296833052 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 0): [<ffffffff991ec485>] __kmalloc_cache_noprof+0x275/0x340 [<ffffffffc0a6e06a>] ice_init_arfs+0x3a/0xe0 [ice] [<ffffffffc09f1027>] ice_vsi_cfg_def+0x607/0x850 [ice] [<ffffffffc09f244b>] ice_vsi_setup+0x5b/0x130 [ice] [<ffffffffc09c2131>] ice_init+0x1c1/0x460 [ice] [<ffffffffc09c64af>] ice_probe+0x2af/0x520 [ice] [<ffffffff994fbcd3>] local_pci_probe+0x43/0xa0 [<ffffffff98f07103>] work_for_cpu_fn+0x13/0x20 [<ffffffff98f0b6d9>] process_one_work+0x179/0x390 [<ffffffff98f0c1e9>] worker_thread+0x239/0x340 [<ffffffff98f14abc>] kthread+0xcc/0x100 [<ffffffff98e45a6d>] ret_from_fork+0x2d/0x50 [<ffffffff98e083ba>] ret_from_fork_asm+0x1a/0x30 ...

Source: NVD