Vulnerability in Linux kernel (CVE-2026-98065)
Summary
Vulnerability in Linux kernel (CVE-2026-98065). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject key-less BTF for hash maps
map_check_btf() allows a key-less BTF (btf_key_type_id == 0) only for
maps that have a ->map_check_btf callback, and leaves the actual
decision to that callback. Hash maps used to have no ->map_check_btf,
so a key-less BTF was rejected outright.
That changed when htab and rhtab gained a ->map_check_btf to register a
dtor - htab in commit 1df97a7453ee ("bpf: Register dtor for freeing
special fields") and rhtab in commit 6905f8601298 ("bpf: Allow special
fields in resizable hashtab"). Neither looks at the key, so a key-less
hash map now passes map_check_btf() and gets created. Reading it back
through bpffs feeds the key type_id 0 into btf_type_seq_show();
btf_type_by_id() returns the void type, kind_ops[BTF_KIND_UNKN] is NULL,
and btf_type_show() dereferences it:
RIP: 0010:btf_type_show+0x223/0x2e0 kernel/bpf/btf.c:8232
RSP: 0018:ffffc9000399f868 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000028
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000399f970 R11: 0000000000000001 R12: ffffffff9b96b140
R13: ffffc9000399f8e0 R14: ffff88803d393c00 R15: 0000000000000003
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 000000003d213000 CR4: 0000000000352ef0
DR0: 0000000039ae8f55 DR1: 0000000000000000 DR2: 0000000000000000
DR3…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-98065 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-98065" on the vendor's site.
CVE-2026-98065 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-98065 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com