CVE-2021-31195

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.5
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 74%
CISA-KEV: Not listedEPSS: 74%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Microsoft Exchange Server Remote Code Execution Vulnerability

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
99.4%
KEV
Not listed

Published

May 11, 2021

Last Modified

February 28, 2025

References (2)

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 10× in last 7d / 29× 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. 2026-07-22 22:47 UTCEG score recompute
  2. 2026-07-22 14:06 UTCEPSS rescore
  3. 2026-07-22 14:06 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-21 15:22 UTCEPSS rescore
  6. 2026-07-20 17:05 UTCEPSS rescore
  7. 2026-07-19 14:28 UTCEPSS rescore
  8. 2026-07-18 10:02 UTCEPSS rescore
  9. 2026-07-18 10:02 UTCEPSS rescore
  10. 2026-07-16 17:00 UTCEPSS rescore
  11. 2026-07-15 16:55 UTCEPSS rescore
  12. 2026-07-15 16:55 UTCEPSS rescore
  13. 2026-07-13 06:10 UTCEPSS rescore
  14. 2026-07-11 08:25 UTCEPSS rescore
  15. 2026-07-11 08:25 UTCEPSS rescore
  16. 2026-07-04 06:29 UTCEPSS rescore
  17. 2026-07-04 06:29 UTCEPSS rescore
  18. 2026-07-01 15:03 UTCEPSS rescore
  19. 2026-06-30 23:20 UTCEPSS rescore
  20. 2026-06-30 23:20 UTCEPSS rescore
  21. 2026-06-29 14:04 UTCEPSS rescore
  22. 2026-06-28 04:54 UTCEPSS rescore
  23. 2026-06-28 04:54 UTCEPSS rescore
  24. 2026-06-25 13:48 UTCEPSS rescore
  25. 2026-06-25 13:48 UTCEPSS rescore
Show 37 more
  1. 2026-06-24 14:03 UTCEPSS rescore
  2. 2026-06-24 14:03 UTCEPSS rescore
  3. 2026-06-23 21:31 UTCEPSS rescore
  4. 2026-06-23 21:31 UTCEPSS rescore
  5. 2026-06-18 17:51 UTCEPSS rescore
  6. 2026-06-18 17:51 UTCEPSS rescore
  7. 2026-06-17 17:51 UTCEPSS rescore
  8. 2026-06-15 17:46 UTCEPSS rescore
  9. 2026-06-12 23:10 UTCEPSS rescore
  10. 2026-06-10 22:16 UTCEPSS rescore
  11. 2026-06-10 13:20 UTCEPSS rescore
  12. 2026-06-07 15:23 UTCEPSS rescore
  13. 2026-06-07 15:23 UTCEPSS rescore
  14. 2026-06-06 13:46 UTCEPSS rescore
  15. 2026-06-06 13:46 UTCEPSS rescore
  16. 2026-06-06 13:46 UTCEPSS rescore
  17. 2026-06-05 22:45 UTCEPSS rescore
  18. 2026-06-05 22:45 UTCEPSS rescore
  19. 2026-06-05 06:09 UTCEPSS rescore
  20. 2026-06-05 06:09 UTCEPSS rescore
  21. 2026-06-02 20:11 UTCEPSS rescore
  22. 2026-06-02 20:11 UTCEPSS rescore
  23. 2026-06-02 20:11 UTCEPSS rescore
  24. 2026-06-01 13:50 UTCEPSS rescore
  25. 2026-06-01 13:50 UTCEPSS rescore
  26. 2026-05-31 00:15 UTCEPSS rescore
  27. 2026-05-29 13:42 UTCEPSS rescore
  28. 2026-05-28 13:43 UTCEPSS rescore
  29. 2026-05-28 13:43 UTCEPSS rescore
  30. 2026-05-27 13:39 UTCEPSS rescore
  31. 2026-05-27 13:39 UTCEPSS rescore
  32. 2026-05-26 16:44 UTCEG score recompute
  33. 2026-05-26 16:44 UTCVendor advisory
  34. 2026-05-26 16:44 UTCGHSA enrichment
  35. 2026-05-26 13:42 UTCEPSS rescore
  36. 2026-05-26 07:17 UTCEPSS rescore
  37. 2026-05-26 07:17 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2021/CVE-2021-31195.yaml
    First seen Jan 1, 2021

    Microsoft Exchange Server - Cross-Site Scripting

    Open source ↗

Frequently asked(5)

What is CVE-2021-31195?
CVE-2021-31195 is a medium vulnerability published on May 11, 2021. Microsoft Exchange Server Remote Code Execution Vulnerability
When was CVE-2021-31195 disclosed?
CVE-2021-31195 was first published in the National Vulnerability Database on May 11, 2021, with the most recent update on February 28, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-31195 actively exploited?
CVE-2021-31195 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-31195?
CVE-2021-31195 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2021-31195?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-31195, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-31195

Explore →

Is Your Infrastructure Affected by CVE-2021-31195?

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

Start Free Scan →Browse All CVEs