Vulnerability in Linux kernel (CVE-2026-98797)
Summary
Vulnerability in Linux kernel (CVE-2026-98797). 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:
net: cap skb->queue_mapping when the tx queue is picked
skbedit can set skb->queue_mapping and raise the per-CPU skip_txqueue
flag so __dev_queue_xmit() honours the mapping. __dev_queue_xmit()
cleared the flag before sch_handle_egress() and only read it afterwards,
so the flag was not confined to the xmit that set it: a nested xmit
(mirred redirect or mirror, or a drop after skbedit) could set the flag
and the outer xmit would consume it for an skb that never went through
skbedit.
A forwarded packet still carries the ingress NIC's rx_queue + 1 in
skb->queue_mapping, so the outer device then indexes its tx queue state
with that stale value. Taprio's child array q->qdiscs[] is sized to the
device's queue count, so taprio_enqueue() indexes past its allocation
and dereferences the result as a struct Qdisc *.
We (ab)use the skb->nf_skip_egress which means "skip netfilter egress
for this packet" to tag to "am I in tc egress?". Despite the overload
I dont see it as a conflict since the marker is set only around the
single sch_handle_egress() call and ingress path is guarded by
tc_at_ingress.
I will send a followup(net-next) patch once this hits net-next to
rename the skb->nf_skip_egress bit/flag to skb->skip_egress
Arm the flag only from the egress classifier that can use it: raise
skip_txqueue from tcf_skbedit_act() only when it runs inside
sch_handle_egress(), thanks to skb->nf_skip_egress. An egress qdisc
cl…
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-2026-98797 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-2026-98797" on the vendor's site.
CVE-2026-98797 (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
- Debian DEBIAN-CVE-2026-98797 linux
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com