CVE-2026-54777

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 98% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 6.5Exploit: 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, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races NamedPipeListener startup between shared memory GUID publication and service named pipe creation. This issue is fixed in versions 1.8.1 and 1.9.1.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

Published

June 19, 2026

Last Modified

July 10, 2026

Advisory Details (5)

Auto-updated Jul 8, 2026
Patch available. Sources: github_commit, github_release, github.
githubMentions a patch (unverified)

CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance · Advisory · CoreWCF/CoreWCF · GitHub

https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-6jj2-4q5c-x8g6
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 e7d225394fd4 (CoreWCF/CoreWCF)

Patch available: CoreWCF/CoreWCF v1.8.1 (contains commit e7d225394fd4)

https://github.com/CoreWCF/CoreWCF/commit/e7d225394fd429900dcbc445dcdd53b94e964077
github_commit

commit 8ed9c780c7c6 (CoreWCF/CoreWCF)

Fix landed in CoreWCF/CoreWCF commit 8ed9c780c7c6 — awaiting tagged release

https://github.com/CoreWCF/CoreWCF/commit/8ed9c780c7c6fb22fa215c5771dee0c1e49596b7

Vendor Advisories for CVE-2026-54777(1)

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

Affected Packages

(1 across 1 ecosystem)
NuGet(1)
PackageVulnerable rangeFix by version rangeDependents
CoreWCF.NetNamedPipe1.9.0
  • 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(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:12 UTCEPSS rescore
  3. 2026-10-07 23:48 UTCEPSS rescore
  4. 2026-10-06 15:18 UTCEPSS rescore
  5. 2026-10-05 17:43 UTCEPSS rescore
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-03 14:26 UTCEPSS rescore
  8. 2026-10-02 17:56 UTCEPSS rescore
  9. 2026-10-02 15:10 UTCOSV refresh
  10. 2026-10-01 19:50 UTCEPSS rescore
  11. 2026-09-30 15:03 UTCEPSS rescore
  12. 2026-09-28 13:51 UTCEPSS rescore
  13. 2026-09-27 13:48 UTCEPSS rescore
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-24 14:04 UTCEPSS rescore
  16. 2026-09-23 17:54 UTCEPSS rescore
  17. 2026-09-18 19:28 UTCEPSS rescore
  18. 2026-09-17 19:31 UTCEPSS rescore
  19. 2026-09-16 14:08 UTCEPSS rescore
  20. 2026-09-16 05:15 UTCEPSS rescore
  21. 2026-09-15 03:11 UTCEPSS rescore
  22. 2026-09-13 16:47 UTCEPSS rescore
  23. 2026-09-13 13:08 UTCEG score recompute
  24. 2026-09-11 14:53 UTCEPSS rescore
  25. 2026-09-10 09:35 UTCEPSS rescore
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  1. 2026-09-08 22:01 UTCEPSS rescore
  2. 2026-09-07 16:01 UTCEPSS rescore
  3. 2026-09-06 13:47 UTCEPSS rescore
  4. 2026-09-04 05:06 UTCEPSS rescore
  5. 2026-09-02 14:12 UTCEPSS rescore
  6. 2026-09-01 13:54 UTCEPSS rescore
  7. 2026-09-01 04:40 UTCEPSS rescore
  8. 2026-08-30 20:47 UTCEG score recompute
  9. 2026-08-30 19:17 UTCEPSS rescore
  10. 2026-08-30 01:22 UTCEPSS rescore
  11. 2026-08-28 21:41 UTCEPSS rescore
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-26 14:46 UTCEPSS rescore
  14. 2026-08-25 01:04 UTCEG score recompute
  15. 2026-08-24 00:20 UTCEG score recompute
  16. 2026-08-23 00:19 UTCEPSS rescore
  17. 2026-08-22 23:39 UTCEG score recompute
  18. 2026-08-21 23:49 UTCEPSS rescore
  19. 2026-08-20 07:59 UTCEG score recompute
  20. 2026-08-19 17:04 UTCEPSS rescore
  21. 2026-08-19 07:00 UTCEG score recompute
  22. 2026-08-17 13:47 UTCEPSS rescore
  23. 2026-08-17 01:19 UTCEG score recompute
  24. 2026-08-16 14:56 UTCEPSS rescore
  25. 2026-08-16 02:14 UTCEPSS rescore
  26. 2026-08-16 00:38 UTCEG score recompute
  27. 2026-08-15 01:30 UTCEPSS rescore
  28. 2026-08-08 19:50 UTCEG score recompute
  29. 2026-08-08 16:37 UTCEPSS rescore
  30. 2026-08-07 19:09 UTCEG score recompute
  31. 2026-08-06 18:28 UTCEG score recompute
  32. 2026-08-05 19:17 UTCEPSS rescore
  33. 2026-08-04 15:19 UTCEG score recompute
  34. 2026-08-04 15:10 UTCEPSS rescore
  35. 2026-08-04 10:39 UTCEPSS rescore
  36. 2026-08-03 10:36 UTCEPSS rescore
  37. 2026-08-01 05:02 UTCEG score recompute
  38. 2026-08-01 04:16 UTCEPSS rescore
  39. 2026-07-31 03:47 UTCEG score recompute
  40. 2026-07-29 01:33 UTCEG score recompute
  41. 2026-07-28 15:37 UTCEPSS rescore
  42. 2026-07-27 18:02 UTCEG score recompute
  43. 2026-07-26 16:47 UTCEG score recompute
  44. 2026-07-26 14:54 UTCEPSS rescore
  45. 2026-07-24 14:18 UTCEPSS rescore
  46. 2026-07-23 14:18 UTCEPSS rescore
  47. 2026-07-23 03:19 UTCEG score recompute
  48. 2026-07-22 14:08 UTCEPSS rescore
  49. 2026-07-20 17:08 UTCEPSS rescore
  50. 2026-07-18 10:04 UTCEPSS rescore
  51. 2026-07-16 17:03 UTCEPSS rescore
  52. 2026-07-15 16:57 UTCEPSS rescore
  53. 2026-07-15 16:57 UTCEPSS rescore
  54. 2026-07-15 02:00 UTCEPSS rescore
  55. 2026-07-15 02:00 UTCEPSS rescore
  56. 2026-07-13 22:31 UTCEPSS rescore
  57. 2026-07-13 06:13 UTCEPSS rescore
  58. 2026-07-13 06:13 UTCEPSS rescore
  59. 2026-07-12 05:46 UTCEPSS rescore
  60. 2026-07-11 08:27 UTCEPSS rescore
  61. 2026-07-11 08:27 UTCEPSS rescore
  62. 2026-07-09 19:10 UTCEPSS rescore
  63. 2026-07-09 19:10 UTCEPSS rescore
  64. 2026-06-19 21:25 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-54777?
CVE-2026-54777 is a medium vulnerability 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, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races…
When was CVE-2026-54777 disclosed?
CVE-2026-54777 was first published on June 19, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54777 actively exploited?
CVE-2026-54777 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-2026-54777?
CVE-2026-54777 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-54777?
A fix for CVE-2026-54777 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-54777 are linked in the Vendor Advisories panel on this page.

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