Vulnerability in Linux kernel (CVE-2026-98289)
Summary
Vulnerability in Linux kernel (CVE-2026-98289). 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:
af_unix: Unify scc_index when finalising SCC in __unix_walk_scc().
Commit bfdb01283ee8 ("af_unix: Assign a unique index to SCC.")
changed Tarjan's algorithm to update lowlink with lowlink,
which is called lowpoint (unix_vertex.scc_index).
unix_vertex_dead() assumes all vertices in an SCC share the same
lowpoint, but this is not always true if an SCC has two or more
back edges, depending on the order of DFS.
For example, the graph below has two back edges from B to A
and from C to B.
A --> B --> C
^ | ^ |
----' ----'
If DFS walks through A -> B -> C -> B (-> C -> B) -> A (-> B -> A),
each index and scc_index will be updated as follows.
A --> B --> C C = (3, 3) (index, scc_index)
B = (2, 2)
A = (1, 1)
A ... B ... C C = (3, 2)<-.
^ | B = (2, 2) -'
`----' A = (1, 1)
A ... B ... C C = (3, 2)
^ | . . B = (2, 1)<-.
`----' .... A = (1, 1) -'
Then, unix_vertex_dead() thinks that B is passed to another
SCC with scc_index 2, and the SCC is not garbage-collected.
This does not happen if DFS walks in a different order below
or starts from B.
1 3
A --> B --> C
^ | ^ |
----' ----'
2 4
Let's unify scc_index across the SCC when finalising it.
Note that updating v->index was previously done in unix_scc_dead(),
when called from __unix_walk_scc(), just to save one loop.…
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-2026-98289 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-2026-98289" on the vendor's site.
CVE-2026-98289 (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 nvd.nist.gov
- web github.com