VulnerabilityPublished 18 Oct 2026

CVE-2026-98567: Linux kernel · net: xps: reject an out of range traffic class

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f, 930318290d8509e864c015fe6c9239470b3c579c, 967e10f40a0c6732db299cbe001df0e859196055 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f	Fixed in eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < 930318290d8509e864c015fe6c9239470b3c579c	Fixed in 930318290d8509e864c015fe6c9239470b3c579c
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < 967e10f40a0c6732db299cbe001df0e859196055	Fixed in 967e10f40a0c6732db299cbe001df0e859196055
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < 9e841723ba482d41ecbf90241c756a16cdfea949	Fixed in 9e841723ba482d41ecbf90241c756a16cdfea949
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < 6ea8f643053f33622f9116e4e1db58306ece45e3	Fixed in 6ea8f643053f33622f9116e4e1db58306ece45e3
LinuxLinux	Affected ≥ 184c449f91fef521042970cca46bd5cdfc0e3a37, < 4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910	Fixed in 4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910

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 multiple Linux kernel commits. Users should update their Linux kernel to a version that includes these fixes. No additional mitigation is required as the patch rejects out-of-range traffic classes to prevent the overflow.

Description

A vulnerability in the Linux kernel's network subsystem (net: xps) allows an out-of-range traffic class to be used, leading to a heap out-of-bounds write. This occurs because the system does not properly reject traffic classes that exceed the configured number of traffic classes (dev->num_tc), causing an index overflow in the XPS map. The issue has been fixed in several Linux kernel commits.

Impact

This vulnerability can cause a heap out-of-bounds write in kernel memory, potentially leading to kernel crashes or memory corruption. There is no indication of active exploitation in the wild. The impact is limited to local kernel memory corruption via malformed traffic class configurations.

Summary

The Linux kernel's net: xps component improperly handles traffic classes that exceed the configured number of traffic classes (dev->num_tc). Specifically, arrays dev->tc_to_txq[] and dev->prio_tc_map[] should only reference classes below dev->num_tc. However, netdev_set_num_tc() reduces dev->num_tc without clearing these arrays, leaving stale entries. Functions netdev_txq_to_tc() and netdev_get_prio_tc_map() can return traffic classes >= dev->num_tc. When __netif_set_xps_queue() uses such a class to index into attr_map[], which is sized by dev->num_tc, it causes an out-of-bounds write. This can lead to kernel memory corruption and crashes, as demonstrated by KASAN slab-out-of-bounds errors. The root cause is that lowering dev->num_tc leaves invalid entries behind, and mqprio_destroy() calls netdev_set_num_tc(dev, 0) without resetting the arrays. The vulnerability has been resolved by rejecting out-of-range traffic classes to prevent indexing beyond attr_map[] bounds.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:38 UTC

Technical details

References

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