CVE-2026-52909

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-19. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: 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:

ip6_vti: set netns_immutable on the fallback device.

john1988 and Noam Rathaus reported that vti6_init_net() does not set the netns_immutable flag on the per-netns fallback tunnel device (ip6_vti0).

Other similar tunnel drivers (like ip6_tunnel, sit, ip6_gre, and ip_tunnel) correctly set this flag during their fallback device initialization to prevent them from being moved to another network namespace.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

June 19, 2026

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Jun 28, 2026
No patch confirmed yet.
generic

ip6_vti: set netns_immutable on the fallback device. - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ecf8904067dcba0dad86ece80874841e60317885
generic

ip6_vti: set netns_immutable on the fallback device. - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/dcdce3bc9f08026ff3739ee7339e1bef526fc5f3
generic

ip6_vti: set netns_immutable on the fallback device. - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d289d5307762d1838aaece22c6b6fcad9e8865f9

Vendor Advisories for CVE-2026-52909(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 (145 versions)7.0.13-1—

Data Freshness Timeline

(refreshed 4× in last 7d / 75× 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 260 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-52909?
CVE-2026-52909 is a high vulnerability published on June 19, 2026. In the Linux kernel, the following vulnerability has been resolved: ip6vti: set netnsimmutable on the fallback device. john1988 and Noam Rathaus reported that vti6initnet() does not set the netnsimmutable flag on the per-netns fallback tunnel device (ip6vti0). Other similar tunnel drivers (like…
When was CVE-2026-52909 disclosed?
CVE-2026-52909 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52909 actively exploited?
CVE-2026-52909 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 97.9% of all scored CVEs.
What is the CVSS score of CVE-2026-52909?
CVE-2026-52909 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-52909?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52909, 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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