CVE-2026-46243

HIGHPre-NVD 7.17.8▲
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-01. the CNA's CVSS baseline 7.1; sources differ by 0.7.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this weekElevated
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: 7.1Exploit: Elevated riskExposed: 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
7.1
EG Score
7.8(medium)
EG Risk
51(Track*)
EG Risk 51/100SSVC: 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%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

June 1, 2026

Last Modified

September 1, 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-417.94.202607240132-02026-08-06redhat
redhatrhcos-413.92.202607141229-02026-07-23redhat
redhatkernel-rt-0:3.10.0-1160.155.1.rt56.1307.el72026-07-17redhat
redhatrhcos-416.94.202607021016-02026-07-16redhat
redhatrhcos-4.19.9.6.202606302000-02026-07-09redhat
redhatrhcos-412.86.202606251120-02026-07-09redhat
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-0:5.14.0-570.123.1.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-0:2.6.32-754.61.1.el62026-06-22redhat
redhatkernel-rt-0:5.14.0-284.176.1.rt14.461.el9_22026-06-17redhat
redhatkernel-0:4.18.0-372.196.1.el8_62026-06-17redhat
redhatkernel-0:4.18.0-305.194.1.el8_42026-06-17redhat
redhatkernel-0:5.14.0-284.176.1.el9_22026-06-17redhat
redhatkernel-0:4.18.0-477.147.1.el8_82026-06-17redhat
redhatkernel-0:6.12.0-55.79.1.el10_02026-06-15redhat
redhatkernel-0:5.14.0-687.13.1.el9_82026-06-08redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (53 versions)5.10.257-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (52 versions)6.1.174-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.90-2~bpo12+1 (25 versions)6.12.90-2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (140 versions)7.0.10-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(15)

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 / 49× 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 359 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

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 September 1, 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 0% probability of exploitation in the next 30 days, which ranks it in the top 68.4% of all scored CVEs.
What is the CVSS score of CVE-2026-46243?
CVE-2026-46243 has a CVSS v4.0 base score of 7.1 (CNA self-assessment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.8.
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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-46243

Explore →

Is Your Infrastructure Affected by CVE-2026-46243?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs