VulnerabilityPublished 18 Oct 2026

CVE-2026-98589: Linux kernel · bpf: Reject pkt arguments in mutating subprogs

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in a6c1edfbe240e4377038a0e1d233ad81fde9a21b : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 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 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a6c1edfbe240e4377038a0e1d233ad81fde9a21b, 7.2.9, 0b6b2bb9b90ad1e2d94d18f626258a1dbbdee0ea

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 Linux to a6c1edfbe240e4377038a0e1d233ad81fde9a21b, 7.2.9 or 0b6b2bb9b90ad1e2d94d18f626258a1dbbdee0ea; the Red Hat redhat/kernel package to 7.2.9.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected <7.2.9	Fixed in a6c1edfbe240e4377038a0e1d233ad81fde9a21b 7.2.9 0b6b2bb9b90ad1e2d94d18f626258a1dbbdee0ea
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected <7.2.9	Fixed in 7.2.9

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 in Linux kernel version 7.2.9 and specific commits (a6c1edfbe240e4377038a0e1d233ad81fde9a21b, 0b6b2bb9b90ad1e2d94d18f626258a1dbbdee0ea). Users should upgrade to these versions or later to mitigate this vulnerability.

Description

A vulnerability in the Linux kernel's BPF verifier allowed unsafe passing of PTR_TO_PACKET pointers to mutating subprograms, risking invalid memory assumptions. This flaw was fixed by rejecting BPF code that passes PTR_TO_PACKET pointers to subprograms that may mutate packets, ensuring memory safety across subprogram boundaries.

Impact

This vulnerability could lead to unsafe memory access or corruption within the kernel's BPF subsystem when packet memory is mutated by subprograms, potentially causing kernel instability or security issues. No known exploits in the wild have been reported.

Summary

The Linux kernel's BPF verifier previously did not correctly handle PTR_TO_PACKET registers passed to mutating subprograms. These pointers are represented as PTR_TO_MEM in subprograms, which assumes the memory region remains valid throughout the call. However, packet memory can be invalidated by pskb_* calls during mutation, leading to unsafe memory access. The fix enforces rejection of BPF programs that pass PTR_TO_PACKET pointers to subprograms that may mutate packets, preventing unsafe memory usage by ensuring such pointers are only passed to non-mutating subprograms.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:23 UTC

Technical details

References

Community reviews

Related threats