VulnerabilityPublished 3 Nov 2026

CVE-2026-99267: Linux kernel · io_uring/napi: make stale entries time out after 60s

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in 981621d6eadcd232d4ea748aaeb046337f10d3c1 : update Linux kernel when convenient.

Data as of 3 Nov 2026, 12:13 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in 981621d6eadcd232d4ea748aaeb046337f10d3c1, 18c373f446068972788158c8c7de6e849b04ed98, 3fe820cf35f83534eab72ea73f1a83cfd3cd8079

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 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 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to 981621d6eadcd232d4ea748aaeb046337f10d3c1, 18c373f446068972788158c8c7de6e849b04ed98 or 3fe820cf35f83534eab72ea73f1a83cfd3cd8079.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5, < 981621d6eadcd232d4ea748aaeb046337f10d3c1	Fixed in 981621d6eadcd232d4ea748aaeb046337f10d3c1
LinuxLinux	Affected ≥ 8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5, < 18c373f446068972788158c8c7de6e849b04ed98	Fixed in 18c373f446068972788158c8c7de6e849b04ed98
LinuxLinux	Affected ≥ 8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5, < 3fe820cf35f83534eab72ea73f1a83cfd3cd8079	Fixed in 3fe820cf35f83534eab72ea73f1a83cfd3cd8079
LinuxLinux	Affected =6.9	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =6.9	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available and has been applied in the Linux kernel as indicated by the fixed commit hashes. Users should update to a kernel version including these fixes to resolve the issue.

Description

A vulnerability in the Linux kernel's io_uring/napi subsystem causes stale entries to never time out due to an incorrect timeout calculation. The timeout intended to drop inactive NAPI IDs after 60 seconds is miscalculated, resulting in entries persisting indefinitely and being continuously polled.

Impact

Stale NAPI IDs are never removed from the polling list, causing continuous polling of all previously used socket IDs. This could lead to resource inefficiencies and potential performance degradation in the kernel's io_uring subsystem. There is no indication of direct security compromise or exploitation in the wild.

Summary

The Linux kernel io_uring/napi feature attempts to dynamically track NAPI IDs and remove those not seen for a minute by timing them out. However, the timeout is computed using an incorrect factor (SEC_CONVERSION) that does not represent the number of jiffies per second but a much larger scaled value. This causes the timeout to be set to approximately eight years instead of 60 seconds. On 32-bit systems, the multiplication overflows, further preventing timeout. Consequently, stale entries remain in the polling list indefinitely, causing every socket ID ever used by the ring to be polled on each wait. This issue was fixed in specific commits referenced by their hashes.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2026, 12:00 UTC

Technical details

References

Community reviews

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