Vulnerability in Linux kernel (CVE-2026-89784)
Summary
Vulnerability in Linux kernel (CVE-2026-89784). 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:
SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6
rpcb_register_inet4() and rpcb_register_inet6() store the result of
rpc_sockaddr2uaddr() into map->r_addr without checking it for NULL.
rpc_sockaddr2uaddr() returns NULL when its final kstrdup() fails, and
the unchecked NULL is then carried into the synchronous RPCBPROC_SET
encode path: rpcb_register_call() -> rpc_call_sync() ->
rpcb_enc_getaddr() -> encode_rpcb_string(), whose first statement is
strlen(string), dereferencing NULL and oopsing the kernel.
The crash reproduces under failslab on v6.12; with KASAN the NULL
dereference surfaces as a fault on the shadow of address zero:
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000000 [#1] PREEMPT SMP KASAN
RIP: 0010:strlen (lib/string.c:409)
Call Trace:
encode_rpcb_string (net/sunrpc/rpcb_clnt.c:890)
rpcb_enc_getaddr (net/sunrpc/rpcb_clnt.c:910)
rpcauth_wrap_req_encode (net/sunrpc/auth.c:745)
call_encode (net/sunrpc/clnt.c:1966)
__rpc_execute (net/sunrpc/sched.c:952)
rpc_run_task (net/sunrpc/clnt.c:1243)
rpc_call_sync (net/sunrpc/clnt.c:1272)
rpcb_v4_register (net/sunrpc/rpcb_clnt.c:500)
svc_generic_rpcbind_set
nfsd_rpcbind_set
svc_register
svc_setup_socket
svc_addsock
write_ports
nfsctl_transaction_write
vfs_write
The crash is reachable when an in-kernel RPC service (nfsd, lockd,
nfs-callback) registers with…
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-2026-89784 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-2026-89784" on the vendor's site.
CVE-2026-89784 (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。
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 git.kernel.org
- web nvd.nist.gov
- web github.com