CVE-2023-31436 — qfq_change_class in net/sched/sch_qfq
qfq_change_class in net/sched/sch_qfq.c in the Linux kernel before 6.2.13 allows an out-of-bounds write because lmax can exceed QFQ_MIN_LMAX.
Published
2023-04-28T02:15:09.007
Last modified
2026-10-14T23:17:18.727
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
01What is this vulnerability?
qfq_change_class in net/sched/sch_qfq.c in the Linux kernel before 6.2.13 allows an out-of-bounds write because lmax can exceed QFQ_MIN_LMAX.
02Affected products
No structured affected-product list available — see references below for vendor advisories.
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2023-04-28T02:15:09.007
- Last modified: 2026-10-14T23:17:18.727
09References
- packetstormsecurity.com — http://packetstormsecurity.com/files/173087/Kernel-Live-Patch-Security-Notice-LS…
- packetstormsecurity.com — http://packetstormsecurity.com/files/173757/Kernel-Live-Patch-Security-Notice-LS…
- packetstormsecurity.com — http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LS…
- cdn.kernel.org — https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.2.13
- github.com — https://github.com/torvalds/linux/commit/3037933448f60f9acb705997eae62013ecb81e0…
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2023/06/msg00008.html
- security.netapp.com — https://security.netapp.com/advisory/ntap-20230609-0001/
- www.debian.org — https://www.debian.org/security/2023/dsa-5402
- www.spinics.net — https://www.spinics.net/lists/stable-commits/msg294885.html
- packetstormsecurity.com — http://packetstormsecurity.com/files/173087/Kernel-Live-Patch-Security-Notice-LS…
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