CVE-2026-54776

MEDIUMPre-NVD 4.44.4
EchelonGraph scoreMEDIUM confidence

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

Score 4.4 from GitHub Security Advisory (severity: MODERATE) published 2026-06-19. A secondary CVSS source baseline 4.4; 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-2026-42461 (ENISA EUVD) · GHSA-wjpq-6766-7f5j (GitHub Security Advisories)Source: ENISA EUVD

4.4EG
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: 0.2%CVSS: 4.4Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, a CoreWCF service hosted on Unix Domain Sockets with PosixIdentity client credentials can accept connections that skip the application/unixposix stream upgrade before dispatching messages, bypassing framing-layer identity checks in UnixPosixIdentitySecurityUpgradeProvider. This issue is fixed in versions 1.8.1 and 1.9.1.

CVSS v3
4.4
EG Score
4.4MEDIUMmedium confidence
EG Risk
20
EG Risk 20/100

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)
Severity44% × 45%
Impact severity (EG Severity): CVSS 4.4 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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.
EPSS PROB
0.2%
EPSS %ILE
4th
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 (4.4): severity, escalated by confirmed exploitation. This CVE's 4.4 is its impact severity (EG Severity), not escalated.

EG Severity
4.4 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 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 Vulnrichment) · Technical impact partial (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

June 19, 2026

Last Modified

July 9, 2026

Advisory Details (6)

Auto-updated Jul 8, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub release Patch Available

CoreWCF v1.9.1

Patch available: CoreWCF/CoreWCF v1.9.1

https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1
GitHub release Patch Available

CoreWCF v1.8.1

Patch available: CoreWCF/CoreWCF v1.8.1

https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1
GitHub commit Patch Available

commit f2f1a05927a8 (CoreWCF/CoreWCF)

Patch available: CoreWCF/CoreWCF v1.9.1 (contains commit f2f1a05927a8)

https://github.com/CoreWCF/CoreWCF/commit/f2f1a05927a88b8a75fa0582fa8ed75eb891e463
GitHub commit Patch Available

commit 9af16955e51a (CoreWCF/CoreWCF)

Patch available: CoreWCF/CoreWCF v1.8.1 (contains commit 9af16955e51a)

https://github.com/CoreWCF/CoreWCF/commit/9af16955e51a57348dafce0019e259a092ef7440
GitHub commit

commit 994431268e33 (CoreWCF/CoreWCF)

Fix landed in CoreWCF/CoreWCF commit 994431268e33 — awaiting tagged release

https://github.com/CoreWCF/CoreWCF/commit/994431268e3362c0cd126450fe2a135c202551f3
GitHub advisoryMentions a patch (unverified)

Unix Domain Socket PosixIdentity transport accepts connections that skip the security upgrade · Advisory · CoreWCF/CoreWCF · GitHub

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-wjpq-6766-7f5j

Vendor Advisories for CVE-2026-54776(1)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
nugetCoreWCF.UnixDomainSocket @ 1.8.1 (fixes < 1.8.1)—ghsa
nugetCoreWCF.UnixDomainSocket @ 1.9.1 (fixes >= 1.9.0, < 1.9.1)—ghsa

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)
NuGet(1)
PackageVulnerable rangeFix by version rangeDependents
CoreWCF.UnixDomainSocket1.9.0
  • every version up to 1.8.1: fixed in 1.8.1
  • 1.9.0 up to 1.9.1: fixed in 1.9.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 37× 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 131 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 31 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-11-01 07:44 UTCGHSA enrichmentGHSA-wjpq-6766-7f5j · GitHub severity MODERATE · GitHub CVSS 4.4
  3. 2026-11-01 07:44 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  5. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-10-30 11:25 UTCOSV refresh
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-25 14:19 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  15. 2026-10-22 21:19 UTCEG score recompute
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  19. 2026-10-18 03:30 UTCEG score recompute
  20. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  21. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  22. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  24. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  25. 2026-10-12 15:56 UTCEG score recompute
Show 75 more
  1. 2026-10-11 19:39 UTCEG score recompute
  2. 2026-10-11 16:54 UTCEG score recompute
  3. 2026-10-11 14:17 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  6. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  7. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  8. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  9. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  11. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  13. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  14. 2026-10-02 15:10 UTCOSV refresh
  15. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  16. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  17. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  18. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  19. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  20. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  21. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  22. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  26. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  27. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  28. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  29. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  30. 2026-09-13 13:08 UTCEG score recompute
  31. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  32. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  33. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  34. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  35. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  36. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  37. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  38. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  39. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  40. 2026-08-30 20:47 UTCEG score recompute
  41. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  43. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  44. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  45. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  46. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  47. 2026-08-24 23:51 UTCEG score recompute
  48. 2026-08-23 23:45 UTCEG score recompute
  49. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  50. 2026-08-21 08:08 UTCEG score recompute
  51. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  52. 2026-08-20 07:59 UTCEG score recompute
  53. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  54. 2026-08-19 07:00 UTCEG score recompute
  55. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  56. 2026-08-16 20:24 UTCEG score recompute
  57. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  58. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  59. 2026-08-15 19:14 UTCEG score recompute
  60. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  61. 2026-08-14 19:07 UTCEG score recompute
  62. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  63. 2026-08-12 18:55 UTCEG score recompute
  64. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  65. 2026-08-11 18:49 UTCEG score recompute
  66. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  67. 2026-08-09 18:12 UTCEG score recompute
  68. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  69. 2026-08-08 18:06 UTCEG score recompute
  70. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  71. 2026-08-07 18:00 UTCEG score recompute
  72. 2026-08-06 17:53 UTCEG score recompute
  73. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  74. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  75. 2026-08-04 15:19 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54776?
CVE-2026-54776 is a medium-severity vulnerability; its CVE record was published on June 19, 2026. CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, a CoreWCF service hosted on Unix Domain Sockets with PosixIdentity client credentials can accept connections that skip the application/unixposix stream upgrade before dispatching…
When was the CVE record for CVE-2026-54776 published?
The CVE record for CVE-2026-54776 was published on June 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 July 9, 2026; the record at its source may have been updated since.
Is CVE-2026-54776 actively exploited?
CVE-2026-54776 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54776?
CVE-2026-54776 has a CVSS base score of 4.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-54776?
A fix for CVE-2026-54776 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-54776 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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