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VulnerabilityPublished Updated

CVE-2026-98063: Linux kernel · bpf: Fix NULL-ptr-deref in btf_var_show()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · fixed in ea383b3ea56979ce54c8aa88e6ec67164986c401 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity
Medium

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

EPSS
0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in ea383b3ea56979ce54c8aa88e6ec67164986c401, e472ae0d97865e2021ee668a13eab64013aebf23, e83fcbe3b5d4a1ffb0569bb7c280358065c6017a +5

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Sep 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 to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < ea383b3ea56979ce54c8aa88e6ec67164986c401
Fixed in
  • ea383b3ea56979ce54c8aa88e6ec67164986c401
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < e472ae0d97865e2021ee668a13eab64013aebf23
Fixed in
  • e472ae0d97865e2021ee668a13eab64013aebf23
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < e83fcbe3b5d4a1ffb0569bb7c280358065c6017a
Fixed in
  • e83fcbe3b5d4a1ffb0569bb7c280358065c6017a
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2
Fixed in
  • e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < ca086264e98108b44fdf53971033811a48defe2b
Fixed in
  • ca086264e98108b44fdf53971033811a48defe2b
LinuxLinuxAffected
  • ≥ c4d0bfb45068d853a478b9067a95969b1886a30f, < aec0a9c1579eb9edf534960be592d09481bd7ac3
Fixed in
  • aec0a9c1579eb9edf534960be592d09481bd7ac3

AI-suggested

A fix is available and has been applied in multiple Linux kernel commits. Users should update to a fixed kernel version that includes these patches to mitigate this issue.

Description

A NULL pointer dereference vulnerability exists in the Linux kernel's btf_var_show() function. This occurs because btf_var_show() calls btf_type_id_resolve() without checking if btf->resolved_ids is NULL, which can happen for base BTF data such as vmlinux BTF. This flaw can cause a kernel crash when a BPF program passes a type_id of BTF_KIND_VAR from the vmlinux BTF to bpf_snprintf_btf(). The issue has been fixed by resolving the variable's type directly when resolved_ids is NULL.

References

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