CVE-2026-64383

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 2026-07-25. 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

Also known asEUVD-2026-48927 (ENISA EUVD) · GHSA-j3g4-c7cw-5ch7 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • 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: fix double-free in SMB2_flush() replay

SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time.

Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 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.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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
0.5%
EPSS %ILE
39th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-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 2026-10-31). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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 or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

July 25, 2026

Last Modified

October 19, 2026

Advisory Details (5)

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

smb: client: fix double-free in SMB2_flush() replay - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/878757163eea684750107a31ea134c103863515d
Web page

smb: client: fix double-free in SMB2_flush() replay - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb
Web page

smb: client: fix double-free in SMB2_flush() replay - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a
Web page

smb: client: fix double-free in SMB2_flush() replay - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3407240cde132a4b72d6429a2625a09a2f78adaf
Web page

smb: client: fix double-free in SMB2_flush() replay - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/013a9a3da46c5dabcf18f65ea6a47874ba12a15d

Patch Availability(18)

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux-6.12—
  • every version up to 6.12.100-1~deb12u1: fixed in 6.12.100-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (30 versions)
  • every version up to 6.12.96-1: fixed in 6.12.96-1
—
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
—

Weakness Classification(1)

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

Additional Vendor Advisories

(14)

Data Freshness Timeline

(refreshed 25× in last 7d / 109× 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 712 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 612 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  2. 2026-11-01 14:31 UTCEG score recompute
  3. 2026-11-01 14:31 UTCVendor advisory
  4. 2026-11-01 14:30 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-10-31 13:24 UTCEG score recompute
  7. 2026-10-31 13:24 UTCVendor advisory
  8. 2026-10-31 13:24 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-10-30 12:17 UTCEG score recompute
  11. 2026-10-30 12:17 UTCVendor advisory
  12. 2026-10-30 12:17 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-29 11:11 UTCEG score recompute
  15. 2026-10-29 11:11 UTCVendor advisory
  16. 2026-10-29 11:10 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  18. 2026-10-28 09:59 UTCEG score recompute
  19. 2026-10-28 09:59 UTCVendor advisory
  20. 2026-10-28 09:58 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  22. 2026-10-27 07:59 UTCEG score recompute
  23. 2026-10-27 07:59 UTCVendor advisory
  24. 2026-10-27 07:59 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
Show 75 more
  1. 2026-10-26 04:23 UTCEG score recompute
  2. 2026-10-26 04:23 UTCVendor advisory
  3. 2026-10-26 04:23 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-25 14:12 UTCEG score recompute
  6. 2026-10-25 03:13 UTCEG score recompute
  7. 2026-10-25 03:13 UTCVendor advisory
  8. 2026-10-25 03:13 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-24 02:07 UTCEG score recompute
  11. 2026-10-24 02:07 UTCVendor advisory
  12. 2026-10-24 02:07 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  14. 2026-10-23 01:00 UTCEG score recompute
  15. 2026-10-23 01:00 UTCVendor advisory
  16. 2026-10-23 01:00 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  18. 2026-10-21 23:51 UTCEG score recompute
  19. 2026-10-21 23:51 UTCVendor advisory
  20. 2026-10-21 23:51 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  22. 2026-10-20 22:45 UTCEG score recompute
  23. 2026-10-20 22:45 UTCVendor advisory
  24. 2026-10-20 22:44 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  26. 2026-10-19 21:30 UTCEG score recompute
  27. 2026-10-19 21:30 UTCVendor advisory
  28. 2026-10-19 21:30 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-19 20:43 UTCEG score recompute
  30. 2026-10-19 20:43 UTCVendor advisory
  31. 2026-10-19 20:42 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  33. 2026-10-18 18:55 UTCEG score recompute
  34. 2026-10-18 18:55 UTCVendor advisory
  35. 2026-10-18 18:55 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  37. 2026-10-18 03:22 UTCEG score recompute
  38. 2026-10-17 17:48 UTCEG score recompute
  39. 2026-10-17 17:48 UTCVendor advisory
  40. 2026-10-17 17:48 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  42. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  43. 2026-10-16 16:40 UTCEG score recompute
  44. 2026-10-16 16:40 UTCVendor advisory
  45. 2026-10-16 16:40 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  46. 2026-10-16 15:48 UTCEG score recompute
  47. 2026-10-16 15:48 UTCVendor advisory
  48. 2026-10-16 15:48 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  50. 2026-10-15 15:13 UTCEG score recompute
  51. 2026-10-15 15:13 UTCVendor advisory
  52. 2026-10-15 15:13 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  54. 2026-10-14 09:36 UTCEG score recompute
  55. 2026-10-14 09:36 UTCVendor advisory
  56. 2026-10-14 09:36 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  58. 2026-10-13 07:16 UTCEG score recompute
  59. 2026-10-13 07:16 UTCVendor advisory
  60. 2026-10-13 07:16 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  62. 2026-10-12 15:48 UTCEG score recompute
  63. 2026-10-12 06:09 UTCVendor advisory
  64. 2026-10-12 06:09 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-11 19:32 UTCEG score recompute
  66. 2026-10-11 16:47 UTCEG score recompute
  67. 2026-10-11 14:09 UTCEG score recompute
  68. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  69. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  70. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  71. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  72. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  73. 2026-10-07 04:35 UTCEG score recompute
  74. 2026-10-07 04:35 UTCVendor advisory
  75. 2026-10-07 04:34 UTCGHSA enrichmentGHSA-j3g4-c7cw-5ch7 · GitHub severity CRITICAL · GitHub CVSS 9.8

Frequently asked(5)

What is CVE-2026-64383?
CVE-2026-64383 is a critical-severity vulnerability; its CVE record was published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a…
When was the CVE record for CVE-2026-64383 published?
The CVE record for CVE-2026-64383 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 October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-64383 actively exploited?
CVE-2026-64383 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64383?
CVE-2026-64383 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-2026-64383?
A fix for CVE-2026-64383 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64383 are linked in the Vendor Advisories panel on this page.

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