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

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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
6%
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.

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 (142 versions)7.0.13-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 99× 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 174 total refreshes for this CVE.

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

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 94.3% 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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