CVE-2026-46243

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-01. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this weekElevated
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

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

smb: client: reject userspace cifs.spnego descriptions

cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin.

Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key.

CVSS v3
7.8
EG Score
7.8(medium)
EPSS
27.8%
KEV
Not listed

Published

June 1, 2026

Last Modified

July 22, 2026

Advisory Details (8)

Auto-updated Jun 4, 2026
No patch confirmed yet.
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
generic

smb: client: reject userspace cifs.spnego descriptions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7713bd320ed4fc3d08a227cd8e41242219a16981

Vendor Advisories for CVE-2026-46243(20)

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

Patch Availability(24)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhcos-412.86.202606251120-02026-07-09redhat
redhatrhcos-4.19.9.6.202606302000-02026-07-09redhat
redhatrhcos-418.94.202606250458-02026-07-08redhat
redhatrhcos-4.20.9.6.202607010620-02026-07-07redhat
redhatrhcos-4.21.9.6.202607011303-02026-07-07redhat
redhatrhcos-415.92.202606200237-02026-07-06redhat
redhatrhcos-414.92.202606231112-02026-07-01redhat
redhatkernel-0:6.12.0-231.12.el10nv2026-06-30redhat
redhatkpatch-patch2026-06-29redhat
redhatkernel-0:2.6.32-754.61.1.el62026-06-22redhat
redhatkernel-0:5.14.0-570.123.1.el9_62026-06-22redhat
redhatkernel-0:3.10.0-1160.153.1.el72026-06-22redhat
redhatkernel-0:5.14.0-427.132.1.el9_42026-06-22redhat
redhatkernel-rt-0:5.14.0-284.176.1.rt14.461.el9_22026-06-17redhat
redhatkernel-0:4.18.0-305.194.1.el8_42026-06-17redhat
redhatkernel-0:4.18.0-477.147.1.el8_82026-06-17redhat
redhatkernel-0:5.14.0-284.176.1.el9_22026-06-17redhat
redhatkernel-0:4.18.0-372.196.1.el8_62026-06-17redhat
redhatkernel-0:6.12.0-55.79.1.el10_02026-06-15redhat
redhatkernel-0:5.14.0-687.13.1.el9_82026-06-08redhat
redhatkernel-0:6.12.0-211.20.1.el10_22026-06-04redhat
redhatkernel-rt-0:4.18.0-553.129.1.rt7.470.el8_102026-06-04redhat
redhatkernel-0:4.18.0-553.129.1.el8_102026-06-04redhat
redhatkernel-0:6.12.0-212.9.el10nv2026-06-04redhat

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.

Weakness Classification(2)

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

Additional Vendor Advisories

(10)

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 13× in last 7d / 91× 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 181 total refreshes for this CVE.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-20 12:37 UTCNVD updateCVSS v3 → 7.8
  5. 2026-07-20 12:17 UTCMITRE cvelistV5CVSS v3 → 7.1
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 02:29 UTCEPSS rescore
  8. 2026-07-18 10:04 UTCEPSS rescore
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-16 12:29 UTCNVD updateCVSS v3 → 7.8
  11. 2026-07-16 12:08 UTCMITRE cvelistV5CVSS v3 → 7.1
  12. 2026-07-16 01:29 UTCVendor advisory
  13. 2026-07-16 01:29 UTCGHSA enrichment
  14. 2026-07-15 16:57 UTCEPSS rescore
  15. 2026-07-15 02:26 UTCNVD updateCVSS v3 → 7.8
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 7.1
  18. 2026-07-14 18:28 UTCVendor advisory
  19. 2026-07-14 18:27 UTCGHSA enrichment
  20. 2026-07-14 05:30 UTCVendor advisory
  21. 2026-07-14 05:30 UTCGHSA enrichment
  22. 2026-07-13 22:30 UTCEPSS rescore
  23. 2026-07-13 06:13 UTCEPSS rescore
  24. 2026-07-12 05:46 UTCEPSS rescore
  25. 2026-07-12 02:21 UTCVendor advisory
Show 75 more
  1. 2026-07-12 02:20 UTCGHSA enrichment
  2. 2026-07-11 13:28 UTCVendor advisory
  3. 2026-07-11 13:28 UTCGHSA enrichment
  4. 2026-07-11 08:27 UTCEPSS rescore
  5. 2026-07-10 12:26 UTCNVD updateCVSS v3 → 7.8
  6. 2026-07-10 12:12 UTCMITRE cvelistV5CVSS v3 → 7.1
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-08 16:55 UTCVendor advisory
  9. 2026-07-08 16:55 UTCGHSA enrichment
  10. 2026-07-08 15:16 UTCEPSS rescore
  11. 2026-07-08 14:36 UTCNVD updateCVSS v3 → 7.8
  12. 2026-07-08 12:47 UTCMITRE cvelistV5CVSS v3 → 7.1
  13. 2026-07-07 14:14 UTCNVD updateCVSS v3 → 7.8
  14. 2026-07-07 13:46 UTCEPSS rescore
  15. 2026-07-07 12:11 UTCMITRE cvelistV5CVSS v3 → 7.1
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 13:51 UTCNVD updateCVSS v3 → 7.8
  18. 2026-07-06 13:07 UTCMITRE cvelistV5CVSS v3 → 7.1
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-02 14:41 UTCVendor advisory
  23. 2026-07-02 14:41 UTCGHSA enrichment
  24. 2026-07-02 02:07 UTCVendor advisory
  25. 2026-07-02 02:07 UTCGHSA enrichment
  26. 2026-07-01 15:07 UTCEPSS rescore
  27. 2026-07-01 11:52 UTCVendor advisory
  28. 2026-07-01 11:51 UTCGHSA enrichment
  29. 2026-06-30 23:22 UTCEPSS rescore
  30. 2026-06-30 23:19 UTCVendor advisory
  31. 2026-06-30 23:19 UTCGHSA enrichment
  32. 2026-06-30 04:33 UTCNVD updateCVSS v3 → 7.8
  33. 2026-06-30 00:30 UTCVendor advisory
  34. 2026-06-30 00:30 UTCGHSA enrichment
  35. 2026-06-29 14:06 UTCEPSS rescore
  36. 2026-06-29 14:06 UTCEPSS rescore
  37. 2026-06-29 11:37 UTCVendor advisory
  38. 2026-06-29 11:37 UTCGHSA enrichment
  39. 2026-06-28 19:27 UTCVendor advisory
  40. 2026-06-28 19:27 UTCGHSA enrichment
  41. 2026-06-28 14:07 UTCEPSS rescore
  42. 2026-06-28 06:54 UTCVendor advisory
  43. 2026-06-28 06:54 UTCGHSA enrichment
  44. 2026-06-28 04:56 UTCEPSS rescore
  45. 2026-06-28 04:56 UTCEPSS rescore
  46. 2026-06-27 18:22 UTCVendor advisory
  47. 2026-06-27 18:22 UTCGHSA enrichment
  48. 2026-06-27 05:49 UTCVendor advisory
  49. 2026-06-27 05:49 UTCGHSA enrichment
  50. 2026-06-27 03:08 UTCEPSS rescore
  51. 2026-06-26 17:16 UTCVendor advisory
  52. 2026-06-26 17:16 UTCGHSA enrichment
  53. 2026-06-26 04:44 UTCVendor advisory
  54. 2026-06-26 04:44 UTCGHSA enrichment
  55. 2026-06-25 16:04 UTCVendor advisory
  56. 2026-06-25 16:04 UTCGHSA enrichment
  57. 2026-06-25 13:49 UTCEPSS rescore
  58. 2026-06-25 03:31 UTCVendor advisory
  59. 2026-06-25 03:31 UTCGHSA enrichment
  60. 2026-06-24 14:56 UTCVendor advisory
  61. 2026-06-24 14:56 UTCGHSA enrichment
  62. 2026-06-24 14:05 UTCEPSS rescore
  63. 2026-06-24 01:50 UTCVendor advisory
  64. 2026-06-24 01:50 UTCGHSA enrichment
  65. 2026-06-23 21:33 UTCEPSS rescore
  66. 2026-06-23 21:33 UTCEPSS rescore
  67. 2026-06-22 14:25 UTCEPSS rescore
  68. 2026-06-22 14:25 UTCEPSS rescore
  69. 2026-06-21 01:59 UTCEPSS rescore
  70. 2026-06-21 01:59 UTCEPSS rescore
  71. 2026-06-20 14:09 UTCVendor advisory
  72. 2026-06-20 14:09 UTCGHSA enrichment
  73. 2026-06-19 19:26 UTCEPSS rescore
  74. 2026-06-19 19:26 UTCEPSS rescore
  75. 2026-06-18 21:55 UTCVendor advisory

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCMrForkBomb/CIFSwitch-Checker-CVE-2026-46243
    First seen Jun 2, 2026

    Script para comprobar si la vulnerabilidad de Linux CIFSwitch (CVE-2026-46243) nos afecta. Detecta configuraciones potencialmente vulnerables y mitigaciones sin ejecutar exploits.

    Open source ↗
  • GitHub PoCKoshmare-Blossom/CIFSwitch-go
    First seen Jun 1, 2026

    A Go implementation of CIFSwitch (CVE-2026-46243)

    Open source ↗

Frequently asked(5)

What is CVE-2026-46243?
CVE-2026-46243 is a high vulnerability published on June 1, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However,…
When was CVE-2026-46243 disclosed?
CVE-2026-46243 was first published in the National Vulnerability Database on June 1, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-46243 actively exploited?
CVE-2026-46243 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 27.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-46243?
CVE-2026-46243 has a CVSS v3.1 base score of 7.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-46243?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-46243, 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

Explore the affected products and dependency analysis for CVE-2026-46243

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