CVE-2026-52906

HIGHPre-NVD 7.77.7—
EchelonGraph scoreHIGH confidence

Score 7.7 from GitHub Security Advisory (severity: HIGH) published 2026-06-09. the CNA's CVSS baseline 7.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
7.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.7Exploit: NoneExposed: 0

A fix is available — apply it.

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

9p: fix access mode flags being ORed instead of replaced

Since commit 1f3e4142c0eb ("9p: convert to the new mount API"), v9fs_apply_options() applies parsed mount flags with |= onto flags already set by v9fs_session_init(). For 9P2000.L, session_init sets V9FS_ACCESS_CLIENT as the default, so when the user mounts with "access=user", both bits end up set. Access mode checks compare against exact values, so having both bits set matches neither mode.

This causes v9fs_fid_lookup() to fall through to the default switch case, using INVALID_UID (nobody/65534) instead of current_fsuid() for all fid lookups. Root is then unable to chown or perform other privileged operations.

Fix by clearing the access mask before applying the user's choice.

CVSS v3
7.7
EG Score
7.7(high)
EPSS
2.2%
KEV
Not listed

Published

June 9, 2026

Last Modified

June 14, 2026

Advisory Details (2)

Auto-updated Jun 14, 2026
No patch confirmed yet.
generic

9p: fix access mode flags being ORed instead of replaced - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/da2346a48a5a1fed86c3fe3d73c0b60e7b3027c9
generic

9p: fix access mode flags being ORed instead of replaced - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b8f037e87a083291190204b959cda417aaf01058

Vendor Advisories for CVE-2026-52906(1)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oem-7.0 (7.0.0-1008.8) @ resolute2026-07-05ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-27.27) @ resolute2026-07-05ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1014.14) @ resolute2026-07-05ubuntu

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.

All Vendor Advisories

(3)

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 35× in last 7d / 121× 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 121 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-52906?
CVE-2026-52906 is a high vulnerability published on June 9, 2026. In the Linux kernel, the following vulnerability has been resolved: 9p: fix access mode flags being ORed instead of replaced Since commit 1f3e4142c0eb ("9p: convert to the new mount API"), v9fsapplyoptions() applies parsed mount flags with |= onto flags already set by v9fssessioninit(). For…
When was CVE-2026-52906 disclosed?
CVE-2026-52906 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on June 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52906 actively exploited?
CVE-2026-52906 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-52906?
CVE-2026-52906 has a CVSS v4.0 base score of 7.7 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-52906?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52906, 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.

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