Vulnerability in Linux kernel (CVE-2026-89900)
Summary
Vulnerability in Linux kernel (CVE-2026-89900). 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:
media: cec: core: Fix kmemleak due to missed rc_free_device() call
The commit dccc0c3ddf8f ("media: rc: fix race between unregister and
urb/irq callbacks") removed the implicit call to rc_free_device() from
rc_unregister_device(). However, the commit missed to remove the NULL
assignment of adap->rc that is now causing rc_free_device() to never be
called on an allocated rc device.
kmemleak reports following after e.g. dw-hdmi unbind:
unreferenced object 0xffff00010ac10000 (size 4096):
comm "kworker/u16:1", pid 39, jiffies 4294897739
hex dump (first 32 bytes):
20 23 4b 0a 01 00 ff ff 08 00 c1 0a 01 00 ff ff #K.............
08 00 c1 0a 01 00 ff ff 00 00 00 00 00 00 00 00 ................
backtrace (crc e11baccc):
kmemleak_alloc+0x38/0x44
__kmalloc_cache_noprof+0x4a8/0x5e0
rc_allocate_device+0x48/0x2a0
cec_allocate_adapter+0x3ac/0x800
dw_hdmi_cec_probe+0x264/0x634
platform_probe+0xc0/0x188
really_probe+0x4a4/0x8e0
__driver_probe_device+0x2f8/0x440
driver_probe_device+0x60/0x160
__device_attach_driver+0x1a0/0x2a0
bus_for_each_drv+0x100/0x1a0
__device_attach+0x174/0x350
device_initial_probe+0x90/0xb0
bus_probe_device+0x4c/0x120
device_add+0xdec/0x116c
platform_device_add+0x354/0x598
Remove the assignment of adap->rc to NULL to let cec_delete_adapter()
free the allocated rc device after last user of the cec device exits to
fix the…
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-2026-89900 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-2026-89900" on the vendor's site.
CVE-2026-89900 (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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-89900 linux-hwe-edge
References
- 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