CVE-2026-63983

UNRATEDCVSS · not yet scoredTrending — 3 sources updated this week
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS v2: Exploit: None knownExposed: 0

A fix is available — apply it.

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 v3
EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
EG Risk
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 19, 2026

Last Modified

July 30, 2026

Vendor Advisories for CVE-2026-63983(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 7.2~rc5-1~exp1 (496 versions)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (350 versions)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (141 versions)7.0.12-1

All Vendor Advisories

(6)

Data Freshness Timeline

(refreshed 12× in last 7d / 44× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-11 19:38 UTCVendor advisory
  2. 2026-09-11 19:38 UTCGHSA enrichment
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 09:37 UTCEPSS rescore
  5. 2026-09-08 22:01 UTCEPSS rescore
  6. 2026-09-08 02:56 UTCVendor advisory
  7. 2026-09-08 02:56 UTCGHSA enrichment
  8. 2026-09-07 16:01 UTCEPSS rescore
  9. 2026-09-06 13:47 UTCEPSS rescore
  10. 2026-09-05 15:31 UTCEPSS rescore
  11. 2026-09-05 09:59 UTCVendor advisory
  12. 2026-09-05 09:59 UTCGHSA enrichment
  13. 2026-09-04 05:07 UTCEPSS rescore
  14. 2026-09-02 14:12 UTCEPSS rescore
  15. 2026-09-01 04:40 UTCEPSS rescore
  16. 2026-08-30 19:17 UTCEPSS rescore
  17. 2026-08-30 02:53 UTCVendor advisory
  18. 2026-08-30 02:53 UTCGHSA enrichment
  19. 2026-08-30 01:22 UTCEPSS rescore
  20. 2026-08-28 21:42 UTCEPSS rescore
  21. 2026-08-27 14:25 UTCEPSS rescore
  22. 2026-08-26 22:43 UTCVendor advisory
  23. 2026-08-26 22:43 UTCGHSA enrichment
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 70 more
  1. 2026-08-24 05:43 UTCVendor advisory
  2. 2026-08-24 05:43 UTCGHSA enrichment
  3. 2026-08-23 00:19 UTCEPSS rescore
  4. 2026-08-21 23:49 UTCEPSS rescore
  5. 2026-08-21 12:46 UTCVendor advisory
  6. 2026-08-21 12:46 UTCGHSA enrichment
  7. 2026-08-20 22:55 UTCEPSS rescore
  8. 2026-08-19 17:04 UTCEPSS rescore
  9. 2026-08-18 19:50 UTCVendor advisory
  10. 2026-08-18 19:49 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-15 21:28 UTCVendor advisory
  15. 2026-08-15 21:28 UTCGHSA enrichment
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-13 04:32 UTCVendor advisory
  19. 2026-08-13 04:32 UTCGHSA enrichment
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-11 00:00 UTCEPSS rescore
  22. 2026-08-10 11:36 UTCVendor advisory
  23. 2026-08-10 11:36 UTCGHSA enrichment
  24. 2026-08-09 13:47 UTCEPSS rescore
  25. 2026-08-08 16:37 UTCEPSS rescore
  26. 2026-08-07 18:39 UTCVendor advisory
  27. 2026-08-07 18:39 UTCGHSA enrichment
  28. 2026-08-06 13:47 UTCEPSS rescore
  29. 2026-08-05 19:17 UTCEPSS rescore
  30. 2026-08-05 19:17 UTCEPSS rescore
  31. 2026-08-05 01:34 UTCVendor advisory
  32. 2026-08-05 01:34 UTCGHSA enrichment
  33. 2026-08-04 15:10 UTCEPSS rescore
  34. 2026-08-04 10:39 UTCEPSS rescore
  35. 2026-08-03 10:36 UTCEPSS rescore
  36. 2026-08-02 08:37 UTCVendor advisory
  37. 2026-08-02 08:37 UTCGHSA enrichment
  38. 2026-08-02 02:27 UTCEPSS rescore
  39. 2026-08-01 04:16 UTCEPSS rescore
  40. 2026-07-30 16:28 UTCEPSS rescore
  41. 2026-07-30 15:41 UTCEG score recompute
  42. 2026-07-30 15:41 UTCVendor advisory
  43. 2026-07-30 15:41 UTCGHSA enrichment
  44. 2026-07-30 01:30 UTCEPSS rescore
  45. 2026-07-30 01:30 UTCEPSS rescore
  46. 2026-07-29 03:55 UTCGHSA enrichment
  47. 2026-07-28 15:37 UTCEPSS rescore
  48. 2026-07-27 14:14 UTCEPSS rescore
  49. 2026-07-26 14:54 UTCEPSS rescore
  50. 2026-07-26 14:54 UTCEPSS rescore
  51. 2026-07-26 10:58 UTCEG score recompute
  52. 2026-07-26 10:58 UTCVendor advisory
  53. 2026-07-26 10:58 UTCGHSA enrichment
  54. 2026-07-25 14:18 UTCEPSS rescore
  55. 2026-07-25 14:18 UTCEPSS rescore
  56. 2026-07-24 14:18 UTCEPSS rescore
  57. 2026-07-24 14:18 UTCEPSS rescore
  58. 2026-07-23 14:18 UTCEPSS rescore
  59. 2026-07-23 14:18 UTCEPSS rescore
  60. 2026-07-23 03:22 UTCEG score recompute
  61. 2026-07-22 14:08 UTCEPSS rescore
  62. 2026-07-22 14:08 UTCEPSS rescore
  63. 2026-07-21 15:25 UTCEPSS rescore
  64. 2026-07-21 15:25 UTCEPSS rescore
  65. 2026-07-20 17:30 UTCEG score recompute
  66. 2026-07-20 17:30 UTCGHSA enrichment
  67. 2026-07-20 17:08 UTCEPSS rescore
  68. 2026-07-19 17:49 UTCNVD update
  69. 2026-07-19 15:21 UTCEG score recompute
  70. 2026-07-19 15:19 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-63983?
CVE-2026-63983 is a publicly disclosed vulnerability published on July 19, 2026. 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…
When was CVE-2026-63983 disclosed?
CVE-2026-63983 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on July 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63983 actively exploited?
CVE-2026-63983 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.9% of all scored CVEs.
How do I remediate CVE-2026-63983?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63983, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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