CVE-2026-98063: Linux kernel · bpf: Fix NULL-ptr-deref in btf_var_show()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in ea383b3ea56979ce54c8aa88e6ec67164986c401 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
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
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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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
- git.kernel.org/stable/c/5756450c9a702da0efb4a993d0a6766b965736f3 (opens in a new tab)
- git.kernel.org/stable/c/e83fcbe3b5d4a1ffb0569bb7c280358065c6017a (opens in a new tab)
- git.kernel.org/stable/c/e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2 (opens in a new tab)
- git.kernel.org/stable/c/aec0a9c1579eb9edf534960be592d09481bd7ac3 (opens in a new tab)
- git.kernel.org/stable/c/e472ae0d97865e2021ee668a13eab64013aebf23 (opens in a new tab)
- git.kernel.org/stable/c/ca086264e98108b44fdf53971033811a48defe2b (opens in a new tab)
- git.kernel.org/stable/c/ea383b3ea56979ce54c8aa88e6ec67164986c401 (opens in a new tab)
- git.kernel.org/stable/c/5403a383f52fc0905703b488f7c3db4b2447dc58 (opens in a new tab)