Vulnerability in Linux kernel (CVE-2026-90423)
Summary
Vulnerability in Linux kernel (CVE-2026-90423). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix UAF in ODP init error-handling path
rxe_odp_mr_init_user() stores &umem_odp->umem in mr->umem before
calling rxe_odp_init_pages(). If rxe_odp_init_pages() fails,
rxe_odp_mr_init_user() releases umem_odp and returns an error.
rxe_reg_user_mr() then unwinds the error through rxe_cleanup(),
rxe_mr_cleanup(), ib_umem_release(mr->umem). There is an
IS_ERR_OR_NULL(umem) check at the start of ib_umem_release().
But since mr->umem is NOT reset to NULL in the error handling
path of rxe_odp_mr_init_user(), the check passes and it reads
already-freed fields like umem->is_dmabuf, causing UAF.
Fix the UAF by clearing mr->umem after releasing the failed
ODP umem so the MR cleanup path does not release it again.
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-2026-90423 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90423" on the vendor's site.
CVE-2026-90423 (Linux kernel) — CVSS v3 7.8
Attack vector: local / no user interaction
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: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
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 nvd.nist.gov
- web github.com