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VulnerabilityPublished Updated

CVE-2026-98869: Linux kernel · bpf: Infer zext_dst based on static register liveness analysis

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High : upgrade to 7ce090afbf725e25fff29caacce1eaf8459b1117 soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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 7ce090afbf725e25fff29caacce1eaf8459b1117
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 21 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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.

What to do

Upgrade Linux kernel to 7ce090afbf725e25fff29caacce1eaf8459b1117.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 107e169799057bc6a379ddb625cbe1e51cfc7d72, < 7ce090afbf725e25fff29caacce1eaf8459b1117
Fixed in
  • 7ce090afbf725e25fff29caacce1eaf8459b1117
LinuxLinuxAffected
  • =6.18
Fixed in–

AI-suggested

A patch is available and has been applied in the Linux kernel commit 7ce090afbf725e25fff29caacce1eaf8459b1117. Users and administrators should update affected Linux kernel versions to this fixed release or later. Since this is a kernel vulnerability, applying the official kernel update is the recommended remediation. No other mitigations are indicated by the vendor advisory.

Description

CVE-2026-98869 is a high-severity vulnerability in the Linux kernel's BPF verifier related to incorrect handling of zero extension for 32-bit operations on s390 architecture. The verifier's logic for zero extending the upper half of registers was broken due to removal of certain liveness tracking steps, potentially allowing injection of arbitrary values in upper register halves. This flaw was fixed by replacing the subregister definition logic with a static register liveness analysis that tracks upper and lower halves separately. The vulnerability affects Linux kernel version 6.18 and has been patched in a later commit.

References

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