CVE-2026-48517

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 72% 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, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's typeless deserialization includes MessagePackSerializerOptions.ThrowIfDeserializingTypeIsDisallowed(Type) as a safety check for dangerous types. The default implementation checks the outer type name, but it does not recursively inspect array element types or generic type arguments. As a result, a type that would be blocked directly can be wrapped inside an array or constructed generic type and pass the outer type check. The formatter machinery can then materialize formatters for the inner blocked type. This vulnerability is fixed in 2.5.301 and 3.1.7.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
34
EG Risk 34/100

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
Severity75% × 45%
Exploitation0% × 40%
Automatability0% × 15%
EPSS PROB
0.3%
EPSS %ILE
26th
KEV
Not listed

Published

June 22, 2026

Last Modified

June 25, 2026

Advisory Details (1)

Auto-updated Jun 23, 2026
Patch available. Sources: github.
githubMentions a patch (unverified)

Typeless deserialization type restrictions do not recurse into arrays or generic arguments · Advisory · MessagePack-CSharp/MessagePack-CSharp · GitHub

https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-qhmf-xw27-6rqr

Vendor Advisories for CVE-2026-48517(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
MessagePack3.0.111-alpha ... 3.1.6 (15 versions)
  • every version up to 2.5.301: fixed in 2.5.301
  • 3.0 up to 3.1.7: fixed in 3.1.7
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 25× 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.

Showing the most recent 100 of 134 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-48517?
CVE-2026-48517 is a high vulnerability published on June 22, 2026. MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's typeless deserialization includes MessagePackSerializerOptions.ThrowIfDeserializingTypeIsDisallowed(Type) as a safety check for dangerous types. The default implementation checks the outer type…
When was CVE-2026-48517 disclosed?
CVE-2026-48517 was first published on June 22, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48517 actively exploited?
CVE-2026-48517 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (26th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-48517?
CVE-2026-48517 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-48517?
A fix for CVE-2026-48517 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-48517 are linked in the Vendor Advisories panel on this page.

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