Vulnerability in Linux kernel (CVE-2026-89796)
Summary
Vulnerability in Linux kernel (CVE-2026-89796). 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:
mm/damon/core: avoid infinite kdamond_merge_regions() internal loop
Patch series "mm/damon: unurgent fixes for infinite loop, NULL de-ref and
races", v1.1.
Sashiko found a few issues in DAMON that could cause infinite loop, NULL
dereference and monitoring results degradation. The first two sounds
scary but the infinite loop happens only under unreasonable user setup.
The NULL dereference is only in a unit test. Monitoring results
degradation is trivial since it is only best-effort, and those happens
from only unlikely races. Still those are bugs that better to fix if
possible. Fix those.
This patch (of 6):
Due to online parameter update like events, the number of DAMON regions
could be higher than the user-set upper limit. kdamond_merge_regions()
repeats merge regions until the number meets the limit, while doubling the
merge threshold up to the theoretical maximum threshold. It is tried only
up to the theoretical maximum threshold because even the aggressive
merging can fail from reducing the number of regions under the
user-defined upper limit. For example, there could be many user-defined
non-contiguous regions that cannot be merged.
The threshold based loop break condition is evaluated by comparing the
threshold for the next merging try against the theoretical maximum
threshold. If max_thres is larger than UINT_MAX / 2, doubling the
threshold could make it overflow, and bypass the loop brea…
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-2026-89796 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-2026-89796" on the vendor's site.
CVE-2026-89796 (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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-89796 linux Fixed in: 6.1.190-1
- Ubuntu UBUNTU-CVE-2026-89796 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package 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 github.com