CVE-2026-90109: Linux kernel · net: sched: fix 32-bit backlog wrap in gred, bfifo and plug enqueue
Source GCVE Database
Not known to be exploited · fixed in d98b92f3d57976ae185238946ec5ea0be32195aa : patch Linux kernel soon.
Data as of 30 Oct 2026, 19:18 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in d98b92f3d57976ae185238946ec5ea0be32195aa, c5ca77024812563fe15c4f7aa906791c3683e9fd, 771a1123570b487765bcf2d4cff3567e66bf1322 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 2026
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 30 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 has been implemented that promotes the backlog sums to 64-bit integers, preventing wraparound and unbounded queue growth. Users should apply the official kernel update containing this fix once available. Until patched, exploitation requires root access and a highly unusual configuration, so typical systems are unlikely to be affected.
Description
A vulnerability in the Linux kernel's network scheduler components gred, bfifo, and plug enqueue allows a 32-bit backlog counter to wrap around when the true backlog exceeds 4 GiB. This causes the admission check to incorrectly succeed, leading to unbounded queue growth and potential out-of-memory (OOM) conditions. The issue requires root privileges and a specially crafted setup to reproduce.
References
- nvd.nist.gov/vuln/detail/CVE-2026-90109 (opens in a new tab)
- git.kernel.org/stable/c/3fb51b3960342bbee563543f8d33710fd0fb5a96 (opens in a new tab)
- git.kernel.org/stable/c/4c660ee8c809637909f4f7eb1017f7b9401c75c4 (opens in a new tab)
- git.kernel.org/stable/c/771a1123570b487765bcf2d4cff3567e66bf1322 (opens in a new tab)
- git.kernel.org/stable/c/8b2d8c70b969bf84f9e248bfaf2a7135129f2eb6 (opens in a new tab)
- git.kernel.org/stable/c/c5ca77024812563fe15c4f7aa906791c3683e9fd (opens in a new tab)
- git.kernel.org/stable/c/d98b92f3d57976ae185238946ec5ea0be32195aa (opens in a new tab)