CVE-2026-53263

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-06-25. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

6lowpan: fix off-by-one in multicast context address compression

The second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses &data[1] as destination and &ipaddr->s6_addr[11] as source, but both should be offset by one: &data[2] and &ipaddr->s6_addr[12] respectively.

This off-by-one has two consequences:

  • data[1] is overwritten with s6_addr[11], corrupting the RIID
field in the compressed multicast address
  • data[5] is never written, so uninitialized kernel stack memory
is transmitted over the network via lowpan_push_hc_data(), leaking kernel stack contents

The correct inline data layout must match what the decompression function lowpan_uncompress_multicast_ctx_daddr() expects: data[0..1] = s6_addr[1..2] (flags/scope + RIID) data[2..5] = s6_addr[12..15] (group ID)

Also zero-initialize the data array as a defensive measure against similar bugs in the future.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

June 25, 2026

Last Modified

July 8, 2026

Advisory Details (8)

Auto-updated Jul 8, 2026
No patch confirmed yet.
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f24a58c72a45f4c109f3557a760cc4b60b7a6037
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/da8cbb64b47e9066b40af0de170901caf17b768c
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/da8808463882c3f3c357b072e25053c2121f1419
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c32f30ef5e66adbfa102348e2e8a23776eb007cb
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4485d79617520d84ba5a14515e2b5136007d6deb
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2a58899d11009bffc7b4b32a571858f381121837
generic

6lowpan: fix off-by-one in multicast context address compression - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/06ce6fc106b16dec9b535950db626261be865e5b

Vendor Advisories for CVE-2026-53263(2)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-09-18ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-31.31) @ resolute2026-09-18ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1013.13) @ resolute2026-09-18ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1018.18~24.04.1) @ noble2026-09-18ubuntu

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

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1—
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 (145 versions)7.0.13-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(4)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 47× 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.

Showing the most recent 100 of 205 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 07:28 UTCEG score recompute
  3. 2026-09-18 07:28 UTCVendor advisory
  4. 2026-09-18 07:28 UTCGHSA enrichment
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-13 14:28 UTCVendor advisory
  9. 2026-09-13 14:28 UTCGHSA enrichment
  10. 2026-09-12 15:53 UTCEG score recompute
  11. 2026-09-12 15:53 UTCVendor advisory
  12. 2026-09-12 15:53 UTCGHSA enrichment
  13. 2026-09-11 14:53 UTCEPSS rescore
  14. 2026-09-10 09:35 UTCEPSS rescore
  15. 2026-09-08 22:01 UTCEPSS rescore
  16. 2026-09-07 16:01 UTCEPSS rescore
  17. 2026-09-06 13:47 UTCEPSS rescore
  18. 2026-09-04 05:06 UTCEPSS rescore
  19. 2026-09-02 14:12 UTCEPSS rescore
  20. 2026-09-01 13:54 UTCEPSS rescore
  21. 2026-09-01 04:40 UTCEPSS rescore
  22. 2026-08-30 19:36 UTCEG score recompute
  23. 2026-08-30 19:36 UTCVendor advisory
  24. 2026-08-30 19:36 UTCGHSA enrichment
  25. 2026-08-30 19:17 UTCEPSS rescore
Show 75 more
  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-28 21:41 UTCEPSS rescore
  3. 2026-08-27 23:57 UTCEG score recompute
  4. 2026-08-27 23:57 UTCVendor advisory
  5. 2026-08-27 23:57 UTCGHSA enrichment
  6. 2026-08-27 14:25 UTCEPSS rescore
  7. 2026-08-25 13:49 UTCEPSS rescore
  8. 2026-08-24 13:11 UTCEG score recompute
  9. 2026-08-24 13:11 UTCVendor advisory
  10. 2026-08-24 13:11 UTCGHSA enrichment
  11. 2026-08-23 09:14 UTCEG score recompute
  12. 2026-08-23 09:14 UTCVendor advisory
  13. 2026-08-23 09:14 UTCGHSA enrichment
  14. 2026-08-23 00:19 UTCEPSS rescore
  15. 2026-08-22 10:39 UTCEG score recompute
  16. 2026-08-22 10:39 UTCVendor advisory
  17. 2026-08-22 10:39 UTCGHSA enrichment
  18. 2026-08-21 23:49 UTCEPSS rescore
  19. 2026-08-21 05:41 UTCEG score recompute
  20. 2026-08-21 05:41 UTCVendor advisory
  21. 2026-08-21 05:41 UTCGHSA enrichment
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-20 07:05 UTCEG score recompute
  24. 2026-08-20 07:05 UTCVendor advisory
  25. 2026-08-20 07:05 UTCGHSA enrichment
  26. 2026-08-19 17:04 UTCEPSS rescore
  27. 2026-08-19 01:30 UTCEG score recompute
  28. 2026-08-19 01:30 UTCVendor advisory
  29. 2026-08-19 01:30 UTCGHSA enrichment
  30. 2026-08-18 13:48 UTCEPSS rescore
  31. 2026-08-17 13:47 UTCEPSS rescore
  32. 2026-08-17 00:20 UTCEG score recompute
  33. 2026-08-17 00:20 UTCVendor advisory
  34. 2026-08-17 00:20 UTCGHSA enrichment
  35. 2026-08-16 14:56 UTCEPSS rescore
  36. 2026-08-16 02:14 UTCEPSS rescore
  37. 2026-08-16 01:45 UTCVendor advisory
  38. 2026-08-16 01:45 UTCGHSA enrichment
  39. 2026-08-15 03:10 UTCEG score recompute
  40. 2026-08-15 03:10 UTCVendor advisory
  41. 2026-08-15 03:10 UTCGHSA enrichment
  42. 2026-08-15 01:30 UTCEPSS rescore
  43. 2026-08-14 04:35 UTCEG score recompute
  44. 2026-08-14 04:35 UTCVendor advisory
  45. 2026-08-14 04:35 UTCGHSA enrichment
  46. 2026-08-13 22:00 UTCEPSS rescore
  47. 2026-08-13 06:00 UTCEG score recompute
  48. 2026-08-13 06:00 UTCVendor advisory
  49. 2026-08-13 06:00 UTCGHSA enrichment
  50. 2026-08-12 13:51 UTCEPSS rescore
  51. 2026-08-12 07:24 UTCEG score recompute
  52. 2026-08-12 07:24 UTCVendor advisory
  53. 2026-08-12 07:24 UTCGHSA enrichment
  54. 2026-08-11 08:48 UTCEG score recompute
  55. 2026-08-11 08:48 UTCVendor advisory
  56. 2026-08-11 08:47 UTCGHSA enrichment
  57. 2026-08-11 00:00 UTCEPSS rescore
  58. 2026-08-10 10:12 UTCEG score recompute
  59. 2026-08-10 10:12 UTCGHSA enrichment
  60. 2026-08-09 13:46 UTCEPSS rescore
  61. 2026-08-09 11:37 UTCEG score recompute
  62. 2026-08-09 11:37 UTCVendor advisory
  63. 2026-08-09 11:37 UTCGHSA enrichment
  64. 2026-08-08 16:37 UTCEPSS rescore
  65. 2026-08-08 12:57 UTCEG score recompute
  66. 2026-08-08 12:57 UTCVendor advisory
  67. 2026-08-08 12:57 UTCGHSA enrichment
  68. 2026-08-07 14:21 UTCVendor advisory
  69. 2026-08-07 14:21 UTCGHSA enrichment
  70. 2026-08-06 15:47 UTCEG score recompute
  71. 2026-08-06 15:47 UTCVendor advisory
  72. 2026-08-06 15:47 UTCGHSA enrichment
  73. 2026-08-06 13:47 UTCEPSS rescore
  74. 2026-08-05 19:17 UTCEPSS rescore
  75. 2026-08-05 17:10 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-53263?
CVE-2026-53263 is a medium vulnerability published on June 25, 2026. In the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix off-by-one in multicast context address compression The second memcpy in lowpaniphcmcastctxaddr_compress() uses &data[1] as destination and &ipaddr->s6_addr[11] as source, but both should be offset by one: &data[2] and…
When was CVE-2026-53263 disclosed?
CVE-2026-53263 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53263 actively exploited?
CVE-2026-53263 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 98.3% of all scored CVEs.
What is the CVSS score of CVE-2026-53263?
CVE-2026-53263 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-53263?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53263, 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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