CVE-2026-46243

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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 (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-33668 (ENISA EUVD) · GHSA-3mg7-pfmq-9qfv (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.8Exploit: Public PoCExposed services: Not assessed

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
7.8HIGHmedium confidence
EG Risk
51
EG Risk 51/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

June 1, 2026

Last Modified

October 15, 2026

Advisory Details (8)

Auto-updated Jun 4, 2026
Patch available.
Web page

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

https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
Web page

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

https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
Web page

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

https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
Web page

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

https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d
Web page

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

https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
Web page

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

https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc
Web page

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

https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
Web page

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

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

Patch Availability(25)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatopenshift/ose-rhel-coreos-9:417.94.202607240132-02026-08-06redhat
redhatopenshift/ose-rhel-coreos-9:413.92.202607141229-02026-07-23redhat
redhatkernel-rt-0:3.10.0-1160.155.1.rt56.1307.el72026-07-17redhat
redhatopenshift/ose-rhel-coreos-9:416.94.202607021016-02026-07-16redhat
redhatopenshift/ose-rhel-coreos-8:412.86.202606251120-02026-07-09redhat
redhatopenshift/ose-rhel-coreos-9:4.19.9.6.202606302000-02026-07-09redhat
redhatopenshift/ose-rhel-coreos-9:418.94.202606250458-02026-07-08redhat
redhatopenshift/ose-rhel-coreos-9:4.20.9.6.202607010620-02026-07-07redhat
redhatopenshift/ose-rhel-coreos-9:4.21.9.6.202607011303-02026-07-07redhat
redhatopenshift/ose-rhel-coreos-9:415.92.202606200237-02026-07-06redhat
redhatopenshift/ose-rhel-coreos-9:414.92.202606231112-02026-07-01redhat
redhatkernel-0:6.12.0-231.12.el10nv2026-06-30redhat
redhatkpatch-patch2026-06-29redhat
redhatkernel-0:3.10.0-1160.153.1.el72026-06-22redhat
redhatkernel-0:5.14.0-427.132.1.el9_42026-06-22redhat
redhatkernel-0:5.14.0-570.123.1.el9_62026-06-22redhat
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
linuxKernel @ 5.10.258 (fixes >=2.6.24)—osv

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 rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (53 versions)
  • every version up to 5.10.257-1: fixed in 5.10.257-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (52 versions)
  • every version up to 6.1.174-1: fixed in 6.1.174-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.90-2~bpo12+1 (25 versions)
  • every version up to 6.12.90-2: fixed in 6.12.90-2
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (141 versions)
  • every version up to 7.0.10-1: fixed in 7.0.10-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(15)

Data Freshness Timeline

(refreshed 10× in last 7d / 50× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 416 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 316 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-10-29 07:39 UTCEG score recompute
  6. 2026-10-29 07:39 UTCVendor advisory
  7. 2026-10-29 07:38 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-10-25 14:25 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  16. 2026-10-22 03:08 UTCEG score recompute
  17. 2026-10-22 03:08 UTCVendor advisory
  18. 2026-10-22 03:07 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  19. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  21. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  22. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  23. 2026-10-18 03:37 UTCEG score recompute
  24. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  25. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 30th percentile
Show 75 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  2. 2026-10-15 02:32 UTCEG score recompute
  3. 2026-10-15 02:32 UTCVendor advisory
  4. 2026-10-15 02:32 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  5. 2026-10-15 02:26 UTCNVD updateCVSS v3 → 7.8
  6. 2026-10-15 01:35 UTCEG score recompute
  7. 2026-10-15 01:35 UTCVendor advisory
  8. 2026-10-15 01:35 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  9. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  10. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  11. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  12. 2026-10-12 16:03 UTCEG score recompute
  13. 2026-10-11 19:45 UTCEG score recompute
  14. 2026-10-11 17:00 UTCEG score recompute
  15. 2026-10-11 14:25 UTCEG score recompute
  16. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  17. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  18. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  19. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  20. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  21. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  22. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  23. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  24. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  25. 2026-10-03 13:39 UTCOSV refresh
  26. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  27. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  28. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  29. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  30. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  31. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  32. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  33. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  34. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  35. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  36. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  37. 2026-09-14 06:07 UTCEG score recompute
  38. 2026-09-14 06:07 UTCVendor advisory
  39. 2026-09-14 06:07 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  40. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  41. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  42. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  43. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  44. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  45. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  46. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  47. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  48. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  49. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  50. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  51. 2026-09-01 12:20 UTCEG score recompute
  52. 2026-09-01 12:20 UTCVendor advisory
  53. 2026-09-01 12:19 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  55. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  56. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  57. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  58. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  59. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  60. 2026-08-25 03:52 UTCEG score recompute
  61. 2026-08-25 03:52 UTCVendor advisory
  62. 2026-08-25 03:52 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  63. 2026-08-24 12:25 UTCEG score recompute
  64. 2026-08-24 12:25 UTCVendor advisory
  65. 2026-08-24 12:24 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  66. 2026-08-24 12:22 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  67. 2026-08-24 12:20 UTCMITRE cvelistV5CVSS v3 → 7.1
  68. 2026-08-23 13:50 UTCEG score recompute
  69. 2026-08-23 13:50 UTCVendor advisory
  70. 2026-08-23 13:50 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  71. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  72. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  73. 2026-08-21 14:51 UTCVendor advisory
  74. 2026-08-21 14:50 UTCGHSA enrichmentGHSA-3mg7-pfmq-9qfv · GitHub severity HIGH · GitHub CVSS 7.8
  75. 2026-08-20 23:25 UTCEG score recompute

Publicly available exploits

(2 references)

Public exploit code is referenced for this CVE (2 GitHub PoCs). Defenders should treat patch urgency accordingly.

  • GitHub PoCMrForkBomb/CIFSwitch-Checker-CVE-2026-46243
    Published 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
    Published 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-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-46243 published?
The CVE record for CVE-2026-46243 was published on June 1, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-46243 actively exploited?
CVE-2026-46243 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
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?
A fix for CVE-2026-46243 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-46243 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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