CVE-2026-98011: net/sched: hhf: clamp quantum in change and init paths
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
- Fixed version: Linux Linux 0898c6f9fa9ce2632ae88bd0f34a878ccc6335af, 1113b674307ffddd402524bd1fd9d7d5629b705b, 2c6dd9fc86d446a03728c43f3b96d9ae29aa058f; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0898c6f9fa9ce2632ae88bd0f34a878ccc6335af, 1113b674307ffddd402524bd1fd9d7d5629b705b, 2c6dd9fc86d446a03728c43f3b96d9ae29aa058f; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: net/sched: hhf: clamp quantum in change and init paths hhf_change() accepts any quantum from userspace, including 1. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times under the qdisc lock (a soft lockup / denial of service). Add max(256U, ...) in hhf_change() matching fq_codel_change(). Clamp hhf_init() to [256, 1<<20] matching the siblings, and remove the old fallback that only set quantum=256 on overflow. Conditions to recreate the bug: CONFIG_NET_SCH_HHF=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root hhf tc qdisc change dev dummy0 root hhf quantum 1 stab data 32768 size_log 15 cell_log 0
- Published
- Sep 25, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.1% · 7th percentile
- CWE
- —
Report tools
Action score
0
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 3.14affected
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before a328698d046098e6f55b3b1460cac6bab577be58affected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before c364ad3ab3c8a6bce469a5cbf02881ab1324c5daaffected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before 2c6dd9fc86d446a03728c43f3b96d9ae29aa058faffected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before 6570f326a6a96bedf3d1d1dab6acc9f8c29104ecaffected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before 1113b674307ffddd402524bd1fd9d7d5629b705baffected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before 2e77947bbf6c166e76c038663832d0914418f761affected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before 0898c6f9fa9ce2632ae88bd0f34a878ccc6335afaffected · git
- 10239edf86f137ce4c39b62ea9575e8053c549a0 and later · before eb56a495f59baf6cad5ed80e3ffb9078098b1346affected · git
- before 3.14not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.190-1 | 6.1.190-1 |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 7.2.7-1 | 7.2.7-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-98009Sep 25, 2026 · net/sched: ets: clamp quantum in parse and fallback paths0Monitor
- ← EarlierCVE-2026-98010Sep 25, 2026 · net/sched: drr: clamp quantum in change class0Monitor
- Later →CVE-2026-98012Sep 25, 2026 · net/sched: sfq: clamp quantum in change path0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0898c6f9fa9ce2632ae88bd0f34a878ccc6335af | Vendor (CNA) |
| Linux Linux | 1113b674307ffddd402524bd1fd9d7d5629b705b | Vendor (CNA) |
| Linux Linux | 2c6dd9fc86d446a03728c43f3b96d9ae29aa058f | Vendor (CNA) |
| Linux Linux | 2e77947bbf6c166e76c038663832d0914418f761 | Vendor (CNA) |
| Linux Linux | 6570f326a6a96bedf3d1d1dab6acc9f8c29104ec | Vendor (CNA) |
| Linux Linux | a328698d046098e6f55b3b1460cac6bab577be58 | Vendor (CNA) |
| Linux Linux | c364ad3ab3c8a6bce469a5cbf02881ab1324c5da | Vendor (CNA) |
| Linux Linux | eb56a495f59baf6cad5ed80e3ffb9078098b1346 | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | 6.6.158.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.190-1 · Debian:12 | Package registry (OSV) |
| debian:linux | 6.12.111-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1184 · Sep 28, 2026(Linux Kernel Güvenlik Bildirimi)
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b
- git.kernel.org/stable/c/2c6dd9fc86d446a03728c43f3b96d9ae29aa058f
- git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761
- git.kernel.org/stable/c/6570f326a6a96bedf3d1d1dab6acc9f8c29104ec
- git.kernel.org/stable/c/a328698d046098e6f55b3b1460cac6bab577be58
- git.kernel.org/stable/c/c364ad3ab3c8a6bce469a5cbf02881ab1324c5da
- git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346
Vendor advisories and official records. Exploit/PoC links are deliberately left out.