CVE-2026-98253: Linux kernel · RDMA/ucma: Serialize join and leave on copy_to_user failure
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in ae805d204cf1f15b87d1bf3529b4c649f3519420 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in ae805d204cf1f15b87d1bf3529b4c649f3519420, 83610ee5e498fa5bfcb80031d2b959baea276bf6, 52172e11bd074ccaded21740ffeb67123f01dd00 +7
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Oct 2026
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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
This vulnerability has been fixed in Linux kernel versions 5.10.271, 5.12, and later. Users and administrators should update to these fixed versions to remediate the issue. No additional mitigations are indicated by the vendor advisory.
Description
CVE-2026-98253 is a high-severity vulnerability in the Linux kernel's RDMA/ucma subsystem. It involves a race condition between concurrent multicast join and leave operations that can lead to use-after-free of kernel memory. The flaw arises from improper serialization of join and leave calls when copy_to_user() fails, potentially causing kernel memory corruption and impacting confidentiality, integrity, and availability.
References
- git.kernel.org/stable/c/29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9 (opens in a new tab)
- git.kernel.org/stable/c/52172e11bd074ccaded21740ffeb67123f01dd00 (opens in a new tab)
- git.kernel.org/stable/c/01e29d0d78a8f66f221625720a04939eef5ec1f6 (opens in a new tab)
- git.kernel.org/stable/c/ae805d204cf1f15b87d1bf3529b4c649f3519420 (opens in a new tab)
- git.kernel.org/stable/c/43c4e24bd10370fc976f6220518049ce71419399 (opens in a new tab)
- git.kernel.org/stable/c/01cbdb724c584d7772fd25af2e4dfdf8527ce0d5 (opens in a new tab)
- git.kernel.org/stable/c/83610ee5e498fa5bfcb80031d2b959baea276bf6 (opens in a new tab)
- git.kernel.org/stable/c/662ade4de9ff5eceb0820a9f8e9fac70ba6a815b (opens in a new tab)