CVE-2026-63991

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:

Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

The skb_clone() function can return NULL if memory allocation fails. send_mcast_pkt() calls skb_clone() without checking the return value, which can lead to a NULL pointer dereference in send_pkt() when it dereferences skb->data. Add a NULL check after skb_clone() and skip the peer if the clone fails.

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
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EG Risk
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EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

July 19, 2026

Last Modified

July 30, 2026

References (8)

Vendor Advisories for CVE-2026-63991(1)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-27ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-27ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-27ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16~24.04.1) @ noble2026-08-27ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-27ubuntu

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 ... 5.10.92-2 (54 versions)5.10.259-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
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 (138 versions)7.0.12-1—

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

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

Frequently asked(4)

What is CVE-2026-63991?
CVE-2026-63991 is a publicly disclosed vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: check skbclone() return value in sendmcast_pkt() The skb_clone() function can return NULL if memory allocation fails. sendmcastpkt() calls skb_clone() without checking the return value, which can lead to a NULL…
When was CVE-2026-63991 disclosed?
CVE-2026-63991 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-2026-63991 actively exploited?
CVE-2026-63991 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 92.7% of all scored CVEs.
How do I remediate CVE-2026-63991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63991, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63991

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