Vulnerability in Linux kernel (CVE-2026-90067)
Summary
Vulnerability in Linux kernel (CVE-2026-90067). Risk of unauthorized operations or information disclosure. Exploitable via payload_len.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
libceph: validate banner payload length
When parsing the Ceph messenger v2 protocol banner, the payload_len field
is decoded from the banner prefix. If a client sends a banner with a
payload_len of 0, the kernel sets up a 0-length socket read. This
violates an invariant in the state machine, triggering a warning in
populate_in_iter():
------------[ cut here ]------------
!iov_iter_count(&con->v2.in_iter)
WARNING: net/ceph/messenger_v2.c:3129 at populate_in_iter
net/ceph/messenger_v2.c:3129 [inline], CPU#1: kworker/1:3/5070
WARNING: net/ceph/messenger_v2.c:3129 at ceph_con_v2_try_read+0x6634/0x6810
net/ceph/messenger_v2.c:3159, CPU#1: kworker/1:3/5070
...
Call Trace:
ceph_con_workfn+0x1f5/0x14a0 net/ceph/messenger.c:1575
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
According to the msgr2 protocol specification, the banner payload is
expected to contain at least two 64-bit integers (server_feat and
server_req_feat). Therefore, payload_len must be at least 16 bytes.
Fix this by adding a check in process_banner_prefix() to reject a
payload_len smaller than 16 bytes. This prevents the 0-length read and
correctly abor…
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-2026-90067 has been found in Linux kernel.
Attackers can target a specific entry point like payload_len over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90067" on the vendor's site.
CVE-2026-90067 (Linux kernel) — CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: payload_len / server_feat / server_req_feat
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. Attackers reach the vulnerable code path via payload_len without authentication.
Check the vendor advisory for the affected versions of Linux kernel. Attack surface: payload_len / server_feat / server_req_feat.
Severity: High (CVSS 7.5/10). 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。
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com