Vulnerability in Linux kernel (CVE-2026-89745)
Summary
Vulnerability in Linux kernel (CVE-2026-89745). Risk of unauthorized operations or information disclosure. Exploitable via mmap.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
debugfs: Fix lockdown check for mmap_prepare
Commit 651fdda8406d ("relay: update relay to use mmap_prepare")
changed the mmap file operation to mmap_prepare for relayfs, but
the lockdown check in debugfs was not updated accordingly.
This prevents debugfs from being locked down when the kernel is in
integrity mode if a file uses mmap_prepare but not mmap.
Since the conversion to mmap_prepare across the kernel is not yet
complete, update the lockdown check to look for both mmap and
mmap_prepare to ensure comprehensive coverage.
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-2026-89745 has been found in Linux kernel.
Attackers can target a specific entry point like mmap over the network to misuse the product.
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-2026-89745" on the vendor's site.
CVE-2026-89745 (Linux kernel)
Attack surface: mmap / mmap_prepare
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 mmap.
Check the vendor advisory for the affected versions of Linux kernel. Attack surface: mmap / mmap_prepare.
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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-89745 linux Fixed in: 7.2.6-1
- Ubuntu UBUNTU-CVE-2026-89745 linux-hwe-edge
References
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com