CVE-2026-64136

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-19. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()

Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifs_tcp_ses_lock for tc_lock around tc_count changes.

There was missing lock around tc_count increment inside smb2_find_smb_sess_tcon_unlocked().

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100

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 (value × EchelonGraph’s weight)
Severity98% × 45%
The EG Score, 9.8 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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.
EPSS PROB
0.5%
EPSS %ILE
40th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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

July 19, 2026

Last Modified

August 13, 2026

Advisory Details (5)

Auto-updated Oct 9, 2026
Patch available.
Web page

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd
Web page

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a
Web page

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d
Web page

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41
Web page

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7

Patch Availability(22)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-10-13ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-10-13ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-10-13ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-10-13ubuntu
ubuntulinux-tools-ibm-edge (6.8.0-1066.67~22.04.1) @ jammy2026-10-13ubuntu
ubuntulinux-virtual-6.8 (6.8.0-139.139) @ noble2026-10-13ubuntu
ubuntulinux-tools-oracle-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-13ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1064.67) @ noble2026-10-13ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1064.67+fips1) @ noble2026-10-13ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2053.55) @ noble2026-10-13ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1067.75+fips1) @ noble2026-10-13ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-13ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1061.64) @ noble2026-10-13ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1067.75) @ noble2026-10-13ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1035.38) @ noble2026-10-13ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1036.37) @ noble2026-10-13ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1067.75~22.04.1) @ jammy2026-10-13ubuntu
ubuntulinux-tools-lowlatency-hwe-20.04-edge (6.8.0-139.139.1) @ noble2026-10-13ubuntu
ubuntulinux-tools-azure-edge (7.0.0-1014.14~24.04.1) @ noble2026-10-13ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-10-13ubuntu
redhatkernel-0:5.14.0-687.45.1.el9_82026-09-08redhat
redhatkernel-0:6.12.0-211.50.1.el10_22026-09-01redhat

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

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)
  • every version up to 6.12.94-1: fixed in 6.12.94-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (142 versions)
  • every version up to 7.0.12-1: fixed in 7.0.12-1
—

Additional Vendor Advisories

(20)

Data Freshness Timeline

(refreshed 19× in last 7d / 70× 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 565 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 465 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 10:41 UTCEG score recompute
  2. 2026-10-14 10:41 UTCVendor advisory
  3. 2026-10-14 10:40 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-10-13 08:23 UTCEG score recompute
  6. 2026-10-13 08:23 UTCVendor advisory
  7. 2026-10-13 08:22 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  9. 2026-10-12 15:48 UTCEG score recompute
  10. 2026-10-12 06:10 UTCVendor advisory
  11. 2026-10-12 06:09 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-11 19:32 UTCEG score recompute
  13. 2026-10-11 16:48 UTCEG score recompute
  14. 2026-10-11 14:09 UTCEG score recompute
  15. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  16. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  17. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  19. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  20. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  21. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  22. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  23. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  24. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 50th percentile
Show 75 more
  1. 2026-10-01 12:33 UTCVendor advisory
  2. 2026-10-01 12:32 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-01 08:09 UTCEG score recompute
  4. 2026-10-01 08:09 UTCVendor advisory
  5. 2026-10-01 08:09 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  7. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  8. 2026-09-28 10:54 UTCVendor advisory
  9. 2026-09-28 10:54 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-09-28 06:36 UTCEG score recompute
  11. 2026-09-28 06:36 UTCVendor advisory
  12. 2026-09-28 06:35 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  14. 2026-09-24 13:11 UTCVendor advisory
  15. 2026-09-24 13:11 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-09-24 08:22 UTCVendor advisory
  17. 2026-09-24 08:22 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-09-24 03:34 UTCEG score recompute
  19. 2026-09-24 03:34 UTCVendor advisory
  20. 2026-09-24 03:34 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-09-23 10:15 UTCVendor advisory
  23. 2026-09-23 10:15 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-09-23 06:02 UTCVendor advisory
  25. 2026-09-23 06:02 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-09-23 01:51 UTCEG score recompute
  27. 2026-09-23 01:51 UTCVendor advisory
  28. 2026-09-23 01:50 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  30. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  31. 2026-09-18 08:49 UTCVendor advisory
  32. 2026-09-18 08:49 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-09-18 04:09 UTCEG score recompute
  34. 2026-09-18 04:09 UTCVendor advisory
  35. 2026-09-18 04:09 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-09-17 09:56 UTCVendor advisory
  37. 2026-09-17 09:56 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  38. 2026-09-17 05:16 UTCEG score recompute
  39. 2026-09-17 05:16 UTCVendor advisory
  40. 2026-09-17 05:16 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  42. 2026-09-16 12:53 UTCEG score recompute
  43. 2026-09-16 12:53 UTCVendor advisory
  44. 2026-09-16 12:53 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  46. 2026-09-14 11:31 UTCVendor advisory
  47. 2026-09-14 11:31 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-09-14 07:17 UTCVendor advisory
  49. 2026-09-14 07:17 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-09-14 03:05 UTCVendor advisory
  51. 2026-09-14 03:05 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  52. 2026-09-13 22:53 UTCEG score recompute
  53. 2026-09-13 22:53 UTCVendor advisory
  54. 2026-09-13 22:53 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-09-13 16:07 UTCVendor advisory
  56. 2026-09-13 16:06 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-09-13 11:46 UTCVendor advisory
  58. 2026-09-13 11:46 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-09-13 07:35 UTCVendor advisory
  60. 2026-09-13 07:35 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-09-13 03:23 UTCVendor advisory
  62. 2026-09-13 03:23 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-09-12 19:32 UTCEG score recompute
  64. 2026-09-12 19:32 UTCVendor advisory
  65. 2026-09-12 19:32 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-09-12 14:19 UTCVendor advisory
  67. 2026-09-12 14:19 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-09-12 10:07 UTCVendor advisory
  69. 2026-09-12 10:07 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  70. 2026-09-12 05:54 UTCVendor advisory
  71. 2026-09-12 05:54 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-09-12 01:06 UTCVendor advisory
  73. 2026-09-12 01:06 UTCGHSA enrichmentGHSA-6vvf-f9vp-vcgv · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-09-11 18:40 UTCEG score recompute
  75. 2026-09-11 18:40 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-64136?
CVE-2026-64136 is a critical-severity vulnerability; its CVE record was published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: client: protect tccount increment in smb2findsmbsesstconunlocked() Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifstcpseslock for tclock around tc_count changes. There was…
When was the CVE record for CVE-2026-64136 published?
The CVE record for CVE-2026-64136 was published on July 19, 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 August 13, 2026; the record at its source may have been updated since.
Is CVE-2026-64136 actively exploited?
CVE-2026-64136 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (40th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64136?
CVE-2026-64136 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64136?
A fix for CVE-2026-64136 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64136 are linked in the Vendor Advisories panel on this page.

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