VulnerabilityPublished 18 Oct 2026

CVE-2026-98797: Linux kernel · net: cap skb->queue_mapping when the tx queue is picked

Source GCVE Database

Authoritative record:CVE-2026-98797· High

Not known to be exploited · fixed in f99de42f5c6f8d088063817dad82c3334e87c570 : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:55 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f99de42f5c6f8d088063817dad82c3334e87c570, ea4d4b5dddb5121e64f56fd8e0720bd8b447b63d, c6ec35c8267c84c2094cb485db20c06384fc2bcc +1

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.

ghsa-v27w-cxg4-mgv7

What to do

Upgrade Linux kernel to f99de42f5c6f8d088063817dad82c3334e87c570, ea4d4b5dddb5121e64f56fd8e0720bd8b447b63d, c6ec35c8267c84c2094cb485db20c06384fc2bcc or 2f581814e4e3ea6a5e98f49813dc4c68444a0c4a.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 2f1e85b1aee459b7d0fd981839042c6a38ffaf0c, < f99de42f5c6f8d088063817dad82c3334e87c570	Fixed in f99de42f5c6f8d088063817dad82c3334e87c570
LinuxLinux	Affected ≥ 2f1e85b1aee459b7d0fd981839042c6a38ffaf0c, < ea4d4b5dddb5121e64f56fd8e0720bd8b447b63d	Fixed in ea4d4b5dddb5121e64f56fd8e0720bd8b447b63d
LinuxLinux	Affected ≥ 2f1e85b1aee459b7d0fd981839042c6a38ffaf0c, < c6ec35c8267c84c2094cb485db20c06384fc2bcc	Fixed in c6ec35c8267c84c2094cb485db20c06384fc2bcc
LinuxLinux	Affected ≥ 2f1e85b1aee459b7d0fd981839042c6a38ffaf0c, < 2f581814e4e3ea6a5e98f49813dc4c68444a0c4a	Fixed in 2f581814e4e3ea6a5e98f49813dc4c68444a0c4a
LinuxLinux	Affected =5.19	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to properly scope the skip_txqueue flag and cap skb->queue_mapping values, preventing out-of-bounds access. Users should update to the fixed kernel version once available. No additional mitigation is required as the patch addresses the root cause. Since this is a kernel-level issue triggered by local privileged users, limiting CAP_NET_ADMIN privileges and network namespace access can reduce exposure until patched.

Description

A vulnerability in the Linux kernel's network subsystem involving skb->queue_mapping and the handling of the skip_txqueue flag in packet transmission has been resolved. The flaw allowed a nested transmit operation to improperly consume a flag set by an inner transmit, leading to out-of-bounds array indexing in the taprio scheduler's child qdisc array. This could be triggered by a local user with CAP_NET_ADMIN in a network namespace redirecting packets between devices with differing numbers of TX queues. The issue is fixed by properly scoping the skip_txqueue flag to the correct transmit context and ensuring skb->queue_mapping is capped to valid values.

Impact

A local user with CAP_NET_ADMIN privileges in a network namespace can cause the kernel to perform out-of-bounds memory access in the taprio scheduler's enqueue function by redirecting packets between devices with differing numbers of TX queues. This can lead to kernel memory corruption and potential system instability or crashes. Under KASAN (Kernel Address Sanitizer), this manifests as a slab-out-of-bounds fault. There is no indication of remote exploitation or active exploitation in the wild.

References

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