CVE-2026-98017: Linux kernel · net/sched: defer qdisc freeing after failed creation
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e6662f2100f8d33b0f4d0047c219efd6bba186ea : 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 e6662f2100f8d33b0f4d0047c219efd6bba186ea, 156a3bab69744e9225bb9eff8c5cc53da18d5a2e, 96a27a3e64e7c87abade03fb2ad04ed66992a89a +3
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 25 Sep 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
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in the Linux kernel commits identified by hashes e6662f2100f8d33b0f4d0047c219efd6bba186ea, 156a3bab69744e9225bb9eff8c5cc53da18d5a2e, 96a27a3e64e7c87abade03fb2ad04ed66992a89a, 20bf6fa34b345333971bd4464a322cce87b83f4e, 6a1b49bb9fdf9e8e7aa38e8cd635c0cc4074447d, and 5bfe927c5b4b290fad529186218c728589b4b101. Users and administrators should update affected Linux kernel versions to incorporate these patches. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-98017 is a high-severity vulnerability in the Linux kernel's network scheduler subsystem. It involves improper handling of queueing discipline (qdisc) freeing after a failed creation during an RTM_NEWQDISC request. This flaw can lead to use-after-free conditions where a qdisc is freed synchronously while still potentially in use, risking system stability and security. The issue has been addressed by deferring the freeing of failed qdiscs using an RCU callback mechanism, ensuring safe destruction. The vulnerability affects Linux kernel version 4.16 and has been fixed in subsequent commits.
References
- git.kernel.org/stable/c/96a27a3e64e7c87abade03fb2ad04ed66992a89a (opens in a new tab)
- git.kernel.org/stable/c/6a1b49bb9fdf9e8e7aa38e8cd635c0cc4074447d (opens in a new tab)
- git.kernel.org/stable/c/20bf6fa34b345333971bd4464a322cce87b83f4e (opens in a new tab)
- git.kernel.org/stable/c/156a3bab69744e9225bb9eff8c5cc53da18d5a2e (opens in a new tab)
- git.kernel.org/stable/c/5bfe927c5b4b290fad529186218c728589b4b101 (opens in a new tab)
- git.kernel.org/stable/c/e6662f2100f8d33b0f4d0047c219efd6bba186ea (opens in a new tab)