CVE-2026-31608

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 2026-04-24. The CNA's CVSS baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory
Trending — 4 sources updated this week

Also known asEUVD-2026-25501 (ENISA EUVD) · GHSA-qx6q-mqg9-4px7 (GitHub Security Advisories)Source: ENISA EUVD

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: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()

smb_direct_flush_send_list() already calls smb_direct_free_sendmsg(), so we should not call it again after post_sendmsg() moved it to the batch list.

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 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.
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
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 2026-10-29). 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

April 24, 2026

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Oct 16, 2026
Patch available.
Web page

smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/84ff995ae826aa6bbcc6c7b9ea569ff67c021d72
Web page

smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/830de6eeb9db4cb7e758201fb99328ef4ca4b032
Web page

smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2ba03f46132b0d1a7bafb86e1ef61951a2254023
Web page

smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6968c91fab05b8fc4d6700e0cf34472bb422df25

Vendor Advisories for CVE-2026-31608(1)

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

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1014.14) @ resolute2026-10-29ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-10-29ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1013.13) @ resolute2026-10-29ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-10-29ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-27.27) @ resolute2026-10-29ubuntu
linuxKernel @ 6.18.24 (fixes >=0)—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

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (130 versions)
  • every version up to 6.19.14-1: fixed in 6.19.14-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 26× in last 7d / 83× 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 98 of 505 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 407 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 21:09 UTCEG score recompute
  2. 2026-10-29 21:09 UTCVendor advisory
  3. 2026-10-29 21:09 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-28 19:17 UTCEG score recompute
  6. 2026-10-28 19:17 UTCVendor advisory
  7. 2026-10-28 19:17 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-10-27 17:25 UTCEG score recompute
  10. 2026-10-27 17:25 UTCVendor advisory
  11. 2026-10-27 17:25 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-26 15:33 UTCEG score recompute
  15. 2026-10-26 15:33 UTCVendor advisory
  16. 2026-10-26 15:33 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  18. 2026-10-25 14:36 UTCEG score recompute
  19. 2026-10-25 13:15 UTCEG score recompute
  20. 2026-10-25 13:15 UTCVendor advisory
  21. 2026-10-25 13:15 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  23. 2026-10-24 11:23 UTCEG score recompute
  24. 2026-10-24 11:23 UTCVendor advisory
  25. 2026-10-24 11:23 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 73 more
  1. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  2. 2026-10-23 09:29 UTCEG score recompute
  3. 2026-10-23 09:29 UTCVendor advisory
  4. 2026-10-23 09:29 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-10-22 07:37 UTCEG score recompute
  7. 2026-10-22 07:37 UTCVendor advisory
  8. 2026-10-22 07:36 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-21 05:43 UTCEG score recompute
  11. 2026-10-21 05:43 UTCVendor advisory
  12. 2026-10-21 05:43 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  14. 2026-10-20 03:51 UTCEG score recompute
  15. 2026-10-20 03:51 UTCVendor advisory
  16. 2026-10-20 03:51 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  18. 2026-10-19 01:58 UTCEG score recompute
  19. 2026-10-19 01:58 UTCVendor advisory
  20. 2026-10-19 01:58 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-10-18 03:48 UTCEG score recompute
  23. 2026-10-18 00:05 UTCEG score recompute
  24. 2026-10-18 00:05 UTCVendor advisory
  25. 2026-10-18 00:05 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  27. 2026-10-16 22:12 UTCEG score recompute
  28. 2026-10-16 22:12 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  30. 2026-10-15 18:49 UTCEG score recompute
  31. 2026-10-15 18:49 UTCVendor advisory
  32. 2026-10-15 18:49 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  34. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  35. 2026-10-14 12:28 UTCEG score recompute
  36. 2026-10-14 12:28 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  38. 2026-10-13 10:35 UTCEG score recompute
  39. 2026-10-13 10:35 UTCVendor advisory
  40. 2026-10-13 10:34 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  42. 2026-10-12 16:15 UTCEG score recompute
  43. 2026-10-12 08:37 UTCVendor advisory
  44. 2026-10-12 08:36 UTCGHSA enrichmentGHSA-qx6q-mqg9-4px7 · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-11 19:57 UTCEG score recompute
  46. 2026-10-11 17:10 UTCEG score recompute
  47. 2026-10-11 14:39 UTCEG score recompute
  48. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  49. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  50. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  51. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  52. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  53. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  54. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  55. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  56. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  57. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  58. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  59. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  60. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  61. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  62. 2026-09-23 08:23 UTCOSV refresh
  63. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  64. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  65. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  66. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  67. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  68. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  69. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  70. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  71. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  72. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  73. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile

Frequently asked(5)

What is CVE-2026-31608?
CVE-2026-31608 is a critical-severity vulnerability; its CVE record was published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: server: avoid double-free in smbdirectfreesendmsg after smbdirectflushsend_list() smbdirectflushsendlist() already calls smbdirectfree_sendmsg(), so we should not call it again after post_sendmsg() moved it to the batch list.
When was the CVE record for CVE-2026-31608 published?
The CVE record for CVE-2026-31608 was published on April 24, 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 5, 2026; the record at its source may have been updated since.
Is CVE-2026-31608 actively exploited?
CVE-2026-31608 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-2026-31608?
CVE-2026-31608 has a CVSS base score of 9.8 (the CNA's own assessment, by linux; NVD's own analysis pending).
How do I remediate CVE-2026-31608?
A fix for CVE-2026-31608 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-31608 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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