CVE-2026-98220: Linux kernel · sched_ext: Fix NULL sched deref in kfunc sub-sched error paths
Affects Linux kernelSource CVE Database V5
Not known to be exploited : upgrade to 589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78 or 0a85182723b65ad8bee8131bc38fcf0347d6679b soon.
Data as of 26 Oct 2026, 13:47 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78, 0a85182723b65ad8bee8131bc38fcf0347d6679b
Exploitation 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 Linux kernel to 589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78 or 0a85182723b65ad8bee8131bc38fcf0347d6679b.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix for this vulnerability is available in the Linux kernel commits identified by hashes 589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78 and 0a85182723b65ad8bee8131bc38fcf0347d6679b. Users and administrators should apply these updates to their Linux kernel to prevent kernel crashes caused by this NULL pointer dereference. If you cannot patch yet, avoid running BPF_PROG_TYPE_SYSCALL programs that may trigger these wrappers on exited or idle tasks with sub-schedulers attached.
Description
CVE-2026-98220 is a vulnerability in the Linux kernel's sched_ext subsystem involving NULL pointer dereference in kernel function (kfunc) sub-scheduler error paths. The issue occurs when certain BPF syscall programs call scheduler wrappers on tasks that have no scheduler, such as exited or idle tasks, leading to a kernel oops due to dereferencing a NULL scheduler pointer. This flaw has been fixed by changing the wrappers to safely handle NULL schedulers and refuse calls when appropriate without causing kernel crashes.