VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-98009: Linux kernel · net/sched: ets: clamp quantum in parse and fallback paths

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in de22c30ec5598aca8797f02082d2ee1358dfa3ff : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in de22c30ec5598aca8797f02082d2ee1358dfa3ff, 440b66cc7b56ea38e9b878ae88da91992efaa4c4, 226d2702e74a570f5bfae6115b4706da4b94e5cf +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < de22c30ec5598aca8797f02082d2ee1358dfa3ff	Fixed in de22c30ec5598aca8797f02082d2ee1358dfa3ff
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < 440b66cc7b56ea38e9b878ae88da91992efaa4c4	Fixed in 440b66cc7b56ea38e9b878ae88da91992efaa4c4
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < 226d2702e74a570f5bfae6115b4706da4b94e5cf	Fixed in 226d2702e74a570f5bfae6115b4706da4b94e5cf
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < 99ae477b892e203a37985ebc56f0063e072f7f4b	Fixed in 99ae477b892e203a37985ebc56f0063e072f7f4b
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < 8f80b113dea0bed3c1a31a4224b72775cd9ec52d	Fixed in 8f80b113dea0bed3c1a31a4224b72775cd9ec52d
LinuxLinux	Affected ≥ dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33, < 8b8d782c3b96376217087767dcf662cd3d25f226	Fixed in 8b8d782c3b96376217087767dcf662cd3d25f226

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: ets: clamp quantum in parse and fallback paths ets_qdisc_change() falls back to psched_mtu() with no floor for bands without an explicit quantum. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so a zero psched_mtu on a headerless device makes the deficit-refill loop spin under the qdisc lock. Move the floor into ets_quantum_parse() so explicitly configured quanta are also clamped to [256, 1<<20], not just the fallback path. Conditions to recreate the bug: CONFIG_NET_SCH_ETS=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root ets bands 3 strict 2 quanta 1 1

References

Community reviews

Loading reviews…