VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-98149: Linux kernel · bpf: Fix percpu map update indexing with sparse CPU IDs

Affects Linux kernelSource CVE Database V5

Not known to be exploited : upgrade to c16c62c91e5d6737a9fbb0a541b8b34610470a2b or 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7 soon.

Data as of 26 Oct 2026, 12:55 UTC

Severity

High

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

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 c16c62c91e5d6737a9fbb0a541b8b34610470a2b, 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7

Exploitation 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.

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 Linux kernel to c16c62c91e5d6737a9fbb0a541b8b34610470a2b or 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360, < c16c62c91e5d6737a9fbb0a541b8b34610470a2b	Fixed in c16c62c91e5d6737a9fbb0a541b8b34610470a2b
LinuxLinux	Affected ≥ 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360, < 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7	Fixed in 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7
LinuxLinux	Affected =7.0	Fixed in–

AI-suggested

This issue is fixed in the Linux kernel commits c16c62c91e5d6737a9fbb0a541b8b34610470a2b and 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7. Users and administrators should update to a Linux kernel version including these fixes to remediate the vulnerability.

Description

CVE-2026-98149 is a vulnerability in the Linux kernel's BPF subsystem affecting per-CPU map update indexing when CPU IDs are sparse. The flaw causes incorrect per-CPU values and an out-of-bounds read during updates of per-CPU array, hash, and cgroup storage maps. This occurs because the update code incorrectly calculates source offsets using logical CPU IDs instead of dense offsets, which the lookup paths already use correctly. The issue is fixed in specific Linux kernel commits.

Impact

This vulnerability can cause incorrect per-CPU data updates and out-of-bounds reads in the Linux kernel BPF subsystem when using sparse CPU IDs. While no exploitation in the wild is known, the flaw could lead to kernel memory corruption or instability due to out-of-bounds memory access during BPF map updates.

Summary

The vulnerability in the Linux kernel's BPF subsystem involves incorrect indexing of per-CPU map update buffers when CPU IDs are sparse (non-contiguous). The update paths iterate over possible CPUs but use logical CPU IDs to calculate source offsets, which only works if CPU IDs are contiguous starting at zero. For sparse CPU masks (e.g., CPUs 0, 2, and 3), this causes incorrect per-CPU values and an out-of-bounds read from the update buffer. The fix aligns the update paths to use dense offsets consistent with the lookup paths, preventing the out-of-bounds access and ensuring correct per-CPU value updates.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:28 UTC

Technical details

References

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