CVE-2026-90073net/sched: hhf: clamp quantum before hhf_change() to avoid overflow
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: hhf: clamp quantum before hhf_change() to avoid overflow hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes weight * quantum overflow the signed deficit in hhf_dequeue(), spinning forever. Clamp q->quantum before hhf_change() so both the opt and !opt paths see a sane quantum. Without this, bare "tc qdisc add ... hhf" succeeds with a clamped quantum but "tc qdisc add ... hhf limit 1000" (any option present) fails with -EINVAL because hhf_change() re-validates the unclamped default (sch_hhf.c:559). 256 matches fq_codel's floor and is a sane minimum for a DRR quantum. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 32 days later
· 32 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 2e0f0729f922c8de13801004e2131b57646c7c5f
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 0c66223e90ddb4fd3700965a9241f2fde7bd6bc7
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 20b65bf7ca06e48ec1d62ed8012f71205328dbe4
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < dea2789a9d5ff38bdd77f2e64d550430899e2839
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < fa9c2055f0a60f801ccf286af53d387dc6202c3f
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 2446644b0f6d045b01db6acbaf55552dbec8a59a
- affected 10239edf86f137ce4c39b62ea9575e8053c549a0 – < 2164b512b97bb053e8ce4d6e95576f11bed6a005
- affected 3.14
- unaffected < 3.14
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.110 – ≤ 6.12.*
- unaffected 6.18.52 – ≤ 6.18.*
- unaffected 7.2.6 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/2e0f0729f922c8de13801004e2131b57646c7c5f (opens in a new tab)
- https://git.kernel.org/stable/c/0c66223e90ddb4fd3700965a9241f2fde7bd6bc7 (opens in a new tab)
- https://git.kernel.org/stable/c/20b65bf7ca06e48ec1d62ed8012f71205328dbe4 (opens in a new tab)
- https://git.kernel.org/stable/c/dea2789a9d5ff38bdd77f2e64d550430899e2839 (opens in a new tab)
- https://git.kernel.org/stable/c/fa9c2055f0a60f801ccf286af53d387dc6202c3f (opens in a new tab)
- https://git.kernel.org/stable/c/99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4 (opens in a new tab)
- https://git.kernel.org/stable/c/2446644b0f6d045b01db6acbaf55552dbec8a59a (opens in a new tab)
- https://git.kernel.org/stable/c/2164b512b97bb053e8ce4d6e95576f11bed6a005 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-81934 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-90073)Record last updated .