CVE-2026-63983net/sched: fix packet loop on netem when duplicate is on
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: net/sched: fix packet loop on netem when duplicate is on When netem duplicates a packet it re-enqueues the copy at the root qdisc. If another netem sits in the tree the copy can be duplicated again, recursing until the stack or memory is exhausted. The original duplication guard temporarily zeroed q->duplicate around the re-enqueue, but that does not cover all cases because it is per-qdisc state shared across all concurrent enqueue paths and is not safe without additional locking. Use the skb tc_depth field introduced in an earlier patch: - increment it on the duplicate before re-enqueue - skip duplication for any skb whose tc_depth is already non-zero. This marks the packet itself rather than mutating qdisc state, therefore it is safe regardless of tree topology or concurrency.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Undergoing Analysis
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 0afb51e72855971dba83b3c6b70c547c2d1161fd before 1a298a514ce766c6d0c232991a390fec67af81ad; from 0afb51e72855971dba83b3c6b70c547c2d1161fd before 4ec3a8ca97394f17e73a4d8d4c79c1c78b322772; from 0afb51e72855971dba83b3c6b70c547c2d1161fd before cfb2616042767ab31260d4f39190c381bec8b12e; from 0afb51e72855971dba83b3c6b70c547c2d1161fd before 9552b11e3edabc97cfcd9f29103d5afbce7ae183 | CNA record |
References
- https://git.kernel.org/stable/c/1a298a514ce766c6d0c232991a390fec67af81ad
- https://git.kernel.org/stable/c/4ec3a8ca97394f17e73a4d8d4c79c1c78b322772
- https://git.kernel.org/stable/c/cfb2616042767ab31260d4f39190c381bec8b12e
- https://git.kernel.org/stable/c/9552b11e3edabc97cfcd9f29103d5afbce7ae183
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.