Unknown

CVE-2026-98063 — bpf: Fix NULL-ptr-deref in btf_var_show()

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NULL-ptr-deref in btf_var_show() btf_var_show() calls btf_type_id_resolve() unconditionally, which dereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the vmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is not resolved during parsing. btf_modifier_show() guards this with 'if (btf->resolved_ids)', but btf_var_show() does not. A BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux BTF to bpf_snprintf_btf() thus NULL-derefs: KASAN: probably user-memory-access in range [0x46638-0x4663f] RIP: 0010:btf_var_show (kernel/bpf/btf.c:2929) Call Trace: <TASK> btf_type_show (kernel/bpf/btf.c:8259) btf_type_snprintf_show (kernel/bpf/btf.c:8329) bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047) bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829) __sys_bpf (kernel/bpf/syscall.c:4804) do_syscall_64 (arch/x86/entry/syscall_64.c:84) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK> Resolve the var's type directly with btf_type_skip_modifiers() when resolved_ids is NULL, mirroring btf_modifier_show().

Published Sep 25, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 7% of scored CVEs · Oct 15, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < 5756450c9a702da0efb4a993d0a6766b965736f3≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < e83fcbe3b5d4a1ffb0569bb7c280358065c6017a≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < aec0a9c1579eb9edf534960be592d09481bd7ac3≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < e472ae0d97865e2021ee668a13eab64013aebf23≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < ca086264e98108b44fdf53971033811a48defe2b≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < ea383b3ea56979ce54c8aa88e6ec67164986c401≥ c4d0bfb45068d853a478b9067a95969b1886a30f and < 5403a383f52fc0905703b488f7c3db4b2447dc58 and 1 more version 5.10	Vulnerable	CVE Program (cve.org) e CISA ADP

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Undergoing Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/e472ae0d97865e2021ee668a13eab64013aebf23
NIST National Vulnerability Database
git.kernel.org/stable/c/ca086264e98108b44fdf53971033811a48defe2b
NIST National Vulnerability Database
git.kernel.org/stable/c/5403a383f52fc0905703b488f7c3db4b2447dc58
NIST National Vulnerability Database
git.kernel.org/stable/c/5756450c9a702da0efb4a993d0a6766b965736f3
NIST National Vulnerability Database
git.kernel.org/stable/c/aec0a9c1579eb9edf534960be592d09481bd7ac3
NIST National Vulnerability Database
git.kernel.org/stable/c/e83fcbe3b5d4a1ffb0569bb7c280358065c6017a
NIST National Vulnerability Database
git.kernel.org/stable/c/ea383b3ea56979ce54c8aa88e6ec67164986c401
NIST National Vulnerability Database
git.kernel.org/stable/c/e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 17h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 17h
Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-98063 is "bpf: Fix NULL-ptr-deref in btf_var_show()", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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