CVE-2026-31704

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory published 2026-05-01. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-26513 (ENISA EUVD) · GHSA-xmgr-rx43-m3gf (GitHub Security Advisories)Source: ENISA EUVD

5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow

set_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes in u16 variables. When a file has many POSIX ACL entries, the accumulated size can wrap past 65535, causing the pointer arithmetic (char *)pndace + *size to land within already-written ACEs. Subsequent writes then overwrite earlier entries, and pndacl->size gets a truncated value.

Use check_add_overflow() at each accumulation point to detect the wrap before it corrupts the buffer, consistent with existing check_mul_overflow() usage elsewhere in smbacl.c.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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
0.1%
EPSS %ILE
1st
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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS. 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, 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; 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.

The score's inputs: 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

May 1, 2026

Last Modified

October 15, 2026

Advisory Details (7)

Auto-updated Oct 15, 2026
Patch available.
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e1955a94b6f17f4b058afa955a6f187eb3ed7615
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8d5729350b236896f51379588d9a690b7fafb8db
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/41e53a773db6342ac9a689ee5ba635c31744c9f0
Web page

ksmbd: use check_add_overflow() to prevent u16 DACL size overflow - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/299f962c0b02d048fb45d248b4da493d03f3175d

Vendor Advisories for CVE-2026-31704(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-raspi-realtime-7.0 (7.0.0-1014.14) @ resolute2026-10-15ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1013.13) @ resolute2026-10-15ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-27.27) @ resolute2026-10-15ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-10-15ubuntu
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-10-15ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-10-15ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-10-15ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-10-15ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-10-15ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-10-15ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-10-15ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-10-15ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-10-15ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-10-15ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-10-15ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-10-15ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-10-15ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-10-15ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-10-15ubuntu
linuxKernel @ 6.1.175 (fixes >=5.15.0)—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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)
  • every version up to 6.1.176-1~deb11u1: fixed in 6.1.176-1~deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)
  • every version up to 6.1.176-1: fixed in 6.1.176-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)
  • every version up to 6.12.85-1: fixed in 6.12.85-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.1-1~exp1 (133 versions)
  • every version up to 7.0.3-1: fixed in 7.0.3-1
—

Additional Vendor Advisories

(19)

Data Freshness Timeline

(refreshed 6× in last 7d / 43× 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 95 of 269 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. 5 repeat rows among the latest 100 are merged into the row they repeat. The 174 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-11-03 16:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  5. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  6. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  7. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  9. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  10. 2026-10-27 16:55 UTCOSV refresh
  11. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  13. 2026-10-25 14:36 UTCEG score recompute
  14. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  20. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-18 03:48 UTCEG score recompute
  22. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  24. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-10-15 02:45 UTCEG score recompute
Show 70 more
  1. 2026-10-15 02:44 UTCGHSA enrichmentGHSA-xmgr-rx43-m3gf · GitHub CVSS 5.5
  2. 2026-10-15 02:25 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  3. 2026-10-15 01:52 UTCEG score recompute
  4. 2026-10-15 01:52 UTCVendor advisory
  5. 2026-10-15 01:51 UTCGHSA enrichmentGHSA-xmgr-rx43-m3gf · GitHub CVSS 5.5
  6. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-13 13:54 UTCOSV refresh
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-12 16:15 UTCEG score recompute
  11. 2026-10-11 19:57 UTCEG score recompute
  12. 2026-10-11 17:10 UTCEG score recompute
  13. 2026-10-11 14:39 UTCEG score recompute
  14. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  16. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  17. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  18. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  20. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  22. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  26. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  27. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  28. 2026-09-23 06:15 UTCOSV refresh
  29. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  30. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  31. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  32. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  33. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  34. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  35. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  36. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  37. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  38. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  39. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  40. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  41. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  42. 2026-09-04 00:59 UTCOSV refresh
  43. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  44. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  45. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  46. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  47. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  48. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  49. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  50. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  51. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  52. 2026-08-24 14:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  53. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  54. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  55. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  56. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  57. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  58. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  59. 2026-08-17 13:45 UTCEG score recompute
  60. 2026-08-17 13:45 UTCVendor advisory
  61. 2026-08-17 13:45 UTCGHSA enrichmentGHSA-xmgr-rx43-m3gf · GitHub CVSS 5.5
  62. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  63. 2026-08-16 05:19 UTCEG score recompute
  64. 2026-08-16 05:19 UTCVendor advisory
  65. 2026-08-16 05:19 UTCGHSA enrichmentGHSA-xmgr-rx43-m3gf · GitHub CVSS 5.5
  66. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  67. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  68. 2026-08-14 03:47 UTCEG score recompute
  69. 2026-08-14 03:47 UTCVendor advisory
  70. 2026-08-14 03:47 UTCGHSA enrichmentGHSA-xmgr-rx43-m3gf · GitHub CVSS 5.5

Frequently asked(5)

What is CVE-2026-31704?
CVE-2026-31704 is a medium-severity vulnerability; its CVE record was published on May 1, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: use check_add_overflow() to prevent u16 DACL size overflow set_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes in u16 variables. When a file has many POSIX ACL entries, the accumulated size can wrap past…
When was the CVE record for CVE-2026-31704 published?
The CVE record for CVE-2026-31704 was published on May 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-2026-31704 actively exploited?
CVE-2026-31704 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-31704?
CVE-2026-31704 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-31704?
A fix for CVE-2026-31704 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-31704 are linked in the Vendor Advisories panel on this page.

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