CVE-2021-26701

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 30% (98th percentile of EPSS-scored CVEs). 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: cna:microsoft, epss
Elevated
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 30%CVSS: 8.1Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

.NET Core Remote Code Execution Vulnerability

CVSS v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
52
EG Risk 52/100CISA SSVC

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
Severity81% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
30%
EPSS %ILE
98th
KEV
Not listed

CISA SSVCTrack 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

February 25, 2021

Last Modified

May 28, 2026

Advisory Details (7)

Auto-updated May 28, 2026
Patch available. Sources: microsoft.
generic

[SECURITY] Fedora 32 Update: dotnet3.1-3.1.113-1.fc32 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S2AZOUKMCHT2WBHR7MYDTYXWOBHZW5P5/
generic

[SECURITY] Fedora 33 Update: dotnet3.1-3.1.113-1.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UBOSSX7U6BSHV5RI74FCOW4ITJ5RRJR5/
generic

[SECURITY] Fedora 32 Update: dotnet5.0-5.0.104-1.fc32 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YLFATXASXW4OV2ZBSRP4G55HJH73QPBP/
generic

[SECURITY] Fedora 33 Update: dotnet5.0-5.0.104-1.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WA5WQJVHUL5C4XMJTLY3C67R4WP35EF4/
generic

[SECURITY] Fedora 34 Update: dotnet5.0-5.0.104-1.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TW3ZSJTTMZAFKGW7NJWTVVFZUYYU2SJZ/
generic

[SECURITY] Fedora 34 Update: dotnet3.1-3.1.113-1.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XPUKFHIGP5YNJRRFWKDJ2XRS4WTFJNNK/
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26701

Vendor Advisories for CVE-2021-26701(2)

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 / EcosystemFixed in / PatchReleasedSource
redhatrh-dotnet21-dotnet-0:2.1.522-1.el7_92021-03-09redhat
redhatrh-dotnet31-dotnet-0:3.1.113-1.el7_92021-03-09redhat
redhatrh-dotnet50-dotnet-0:5.0.104-1.el7_92021-03-09redhat
redhatdotnet-0:2.1.522-1.el8_32021-03-09redhat
redhatdotnet3.1-0:3.1.113-1.el8_32021-03-09redhat
redhatdotnet5.0-0:5.0.104-1.el8_32021-03-09redhat

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 rangeFixed inDependents
System.Text.Encodings.Web5.0.05.0.1—

Additional Vendor Advisories

(6)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 7× in last 7d / 28× 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 158 total refreshes for this CVE.

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

Related CVEs(same product)

Frequently asked(5)

What is CVE-2021-26701?
CVE-2021-26701 is a high vulnerability published on February 25, 2021. .NET Core Remote Code Execution Vulnerability
When was CVE-2021-26701 disclosed?
CVE-2021-26701 was first published on February 25, 2021, with the most recent update on May 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-26701 actively exploited?
CVE-2021-26701 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 30% probability of exploitation in the next 30 days (98th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-26701?
CVE-2021-26701 has a CVSS base score of 8.1 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2021-26701?
A fix for CVE-2021-26701 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-26701 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-26701

Explore →

Is Your Infrastructure Affected by CVE-2021-26701?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs