CVE-2026-64390

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-25. A secondary CVSS source baseline 8.8; 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

Also known asEUVD-2026-48934 (ENISA EUVD) · GHSA-pgh2-g34p-4j6m (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
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: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

ksmbd: track the connection owning a byte-range lock

SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths, however, remove the connection list entry while holding fp->conn->llist_lock.

With SMB3 multichannel, the connection handling the LOCK request can be different from the connection which opened the file. The entry can therefore be removed under a different spinlock from the one protecting the list it belongs to. A concurrent traversal can then access freed struct ksmbd_lock and struct file_lock objects.

Record the connection owning each lock's clist entry and hold a reference to it while the entry is linked. Use that connection and its llist_lock for unlock, rollback, close, and durable preserve. Durable reconnect assigns the new connection as the owner when publishing the locks again.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
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

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

The EG score (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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 or medium mission impact; Track* at high (mission-essential systems).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: the SSVC and BOD 26-04 blocks below.

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 25, 2026

Last Modified

September 4, 2026

Advisory Details (7)

Auto-updated Jul 27, 2026
Patch available.
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5fecc15a30cb9ebd310f7b52c1ab607edcea78f6
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/427faaa52b0b399940c1a88065a5c310d10dad15
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fe20d492a69a6f79e637f438072b212e21ed3b78
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ea5c9bf99f626a15cc59f645dc895f2b3f01992e
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/66eb3643164e5e1029907793926c132f8b5c6148
Web page

ksmbd: track the connection owning a byte-range lock - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22d38cf75b556c20b039743bdf3654d535b858be

Vendor Advisories for CVE-2026-64390(2)

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

Patch Availability(20)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1071.79) @ noble2026-10-28ubuntu
ubuntulinux-virtual-6.8 (6.8.0-147.147) @ noble2026-10-28ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1013.13) @ resolute2026-10-28ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1112.112) @ jammy2026-10-28ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1018.18) @ resolute2026-10-28ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2018.18) @ resolute2026-10-28ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1122.131) @ jammy2026-10-28ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-28ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1035.38) @ noble2026-10-28ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1118.128~20.04.1) @ focal2026-10-28ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1118.115) @ jammy2026-10-28ubuntu
ubuntulinux-tools-oracle-edge (5.15.0.1114.120~20.04.1) @ focal2026-10-28ubuntu
ubuntulinux-tools-ibm-7.0 (7.0.0-1013.13) @ resolute2026-10-28ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1011.11) @ resolute2026-10-28ubuntu
ubuntulinux-tools-azure-edge (7.0.0-1014.14~24.04.1) @ noble2026-10-28ubuntu
ubuntulinux-tools-oracle-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-28ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1019.19) @ resolute2026-10-28ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1018.18~24.04.1) @ noble2026-10-28ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-31.31) @ resolute2026-10-28ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1080 (5.15.0-1080.84) @ jammy2026-10-28ubuntu

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

(5 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)
  • every version up to 6.1.180-1: fixed in 6.1.180-1
—
linux-6.12—
  • every version up to 6.12.100-1~deb12u1: fixed in 6.12.100-1~deb12u1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)
  • every version up to 6.1.180-1~deb11u1: fixed in 6.1.180-1~deb11u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)
  • every version up to 6.12.100-1: fixed in 6.12.100-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (159 versions)
  • every version up to 7.1.4-1: fixed in 7.1.4-1
—

All Vendor Advisories

(20)

Data Freshness Timeline

(refreshed 11× in last 7d / 58× 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 300 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 200 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  3. 2026-10-28 15:17 UTCEG score recompute
  4. 2026-10-28 15:17 UTCVendor advisory
  5. 2026-10-28 15:17 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  7. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  8. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  9. 2026-10-25 14:12 UTCEG score recompute
  10. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  12. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-20 20:57 UTCEG score recompute
  15. 2026-10-20 20:57 UTCVendor advisory
  16. 2026-10-20 20:57 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  18. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  19. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  20. 2026-10-18 03:22 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  22. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  23. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  24. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  25. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
Show 75 more
  1. 2026-10-13 11:41 UTCEG score recompute
  2. 2026-10-13 11:41 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  4. 2026-10-12 15:48 UTCEG score recompute
  5. 2026-10-11 19:32 UTCEG score recompute
  6. 2026-10-11 16:47 UTCEG score recompute
  7. 2026-10-11 14:09 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  11. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-07 04:34 UTCEG score recompute
  14. 2026-10-07 04:34 UTCVendor advisory
  15. 2026-10-07 04:34 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  19. 2026-10-04 07:31 UTCEG score recompute
  20. 2026-10-04 07:31 UTCVendor advisory
  21. 2026-10-04 07:31 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-10-02 19:24 UTCEG score recompute
  24. 2026-10-02 19:24 UTCVendor advisory
  25. 2026-10-02 19:23 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  26. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  27. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  28. 2026-10-01 15:45 UTCVendor advisory
  29. 2026-10-01 15:45 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  30. 2026-10-01 04:14 UTCEG score recompute
  31. 2026-10-01 04:14 UTCVendor advisory
  32. 2026-10-01 04:14 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  33. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  34. 2026-09-29 08:27 UTCEG score recompute
  35. 2026-09-29 08:27 UTCVendor advisory
  36. 2026-09-29 08:27 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  37. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  38. 2026-09-28 04:12 UTCEG score recompute
  39. 2026-09-28 04:12 UTCVendor advisory
  40. 2026-09-28 04:12 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  41. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  42. 2026-09-25 08:02 UTCEG score recompute
  43. 2026-09-25 08:02 UTCVendor advisory
  44. 2026-09-25 08:02 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  45. 2026-09-24 09:41 UTCVendor advisory
  46. 2026-09-24 09:41 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-09-23 22:09 UTCEG score recompute
  48. 2026-09-23 22:09 UTCVendor advisory
  49. 2026-09-23 22:09 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  50. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  51. 2026-09-23 09:23 UTCVendor advisory
  52. 2026-09-23 09:23 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  53. 2026-09-22 22:01 UTCEG score recompute
  54. 2026-09-22 22:01 UTCVendor advisory
  55. 2026-09-22 22:00 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  57. 2026-09-20 01:25 UTCEG score recompute
  58. 2026-09-20 01:25 UTCVendor advisory
  59. 2026-09-20 01:25 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  60. 2026-09-18 19:46 UTCEG score recompute
  61. 2026-09-18 19:46 UTCVendor advisory
  62. 2026-09-18 19:46 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  64. 2026-09-18 02:46 UTCEG score recompute
  65. 2026-09-18 02:46 UTCVendor advisory
  66. 2026-09-18 02:46 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  67. 2026-09-17 01:54 UTCEG score recompute
  68. 2026-09-17 01:54 UTCVendor advisory
  69. 2026-09-17 01:54 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  71. 2026-09-16 06:29 UTCEG score recompute
  72. 2026-09-16 06:29 UTCVendor advisory
  73. 2026-09-16 06:29 UTCGHSA enrichmentGHSA-pgh2-g34p-4j6m · GitHub severity HIGH · GitHub CVSS 8.8
  74. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  75. 2026-09-15 09:23 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-64390?
CVE-2026-64390 is a high-severity vulnerability; its CVE record was published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths,…
When was the CVE record for CVE-2026-64390 published?
The CVE record for CVE-2026-64390 was published on July 25, 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 September 4, 2026; the record at its source may have been updated since.
Is CVE-2026-64390 actively exploited?
CVE-2026-64390 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-2026-64390?
CVE-2026-64390 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64390?
A fix for CVE-2026-64390 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64390 are linked in the Vendor Advisories panel on this page.

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