CVE-2021-41349

CRITICALNVD 6.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because EPSS predicts 94% probability of exploitation within the next 30 days (top 0.2% of all CVEs). NVD baseline CVSS 6.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Elevated
9.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 93%
CISA-KEV: Not listedEPSS PROB: 93%CVSS: 6.5Exploit: Elevated riskExposed: 0

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

Microsoft Exchange Server Spoofing Vulnerability

CVSS v3
6.5
EG Score
9.0(high)
EG Risk
83(Track)
EG Risk 83/100SSVC: Track

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
Severity90% × 45%
Exploitation94% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
93%
EPSS %ILE
100%
KEV
Not listed

Published

November 10, 2021

Last Modified

August 19, 2026

Advisory Details (2)

Auto-updated Aug 19, 2026
Patch available. Sources: microsoft.
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-2021-41349
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

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

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-41349

Vendor Advisories for CVE-2021-41349(1)

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

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 3× in last 7d / 17× 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. 2026-09-06 13:45 UTCEPSS rescore
  2. 2026-09-05 15:25 UTCEPSS rescore
  3. 2026-09-04 05:03 UTCEPSS rescore
  4. 2026-09-01 03:33 UTCEPSS rescore
  5. 2026-08-30 19:14 UTCEPSS rescore
  6. 2026-08-30 19:14 UTCEPSS rescore
  7. 2026-08-28 21:37 UTCEPSS rescore
  8. 2026-08-26 14:43 UTCEPSS rescore
  9. 2026-08-25 13:46 UTCEPSS rescore
  10. 2026-08-24 14:13 UTCEPSS rescore
  11. 2026-08-20 22:52 UTCEPSS rescore
  12. 2026-08-20 22:52 UTCEPSS rescore
  13. 2026-08-19 18:06 UTCEG score recompute
  14. 2026-08-19 18:06 UTCVendor advisory
  15. 2026-08-19 18:06 UTCGHSA enrichment
  16. 2026-08-16 14:53 UTCEPSS rescore
  17. 2026-08-12 13:48 UTCEPSS rescore
  18. 2026-08-08 16:33 UTCEPSS rescore
  19. 2026-08-07 16:24 UTCEPSS rescore
  20. 2026-08-01 04:13 UTCEPSS rescore
  21. 2026-07-24 14:15 UTCEPSS rescore
  22. 2026-07-23 14:16 UTCEPSS rescore
  23. 2026-07-23 02:04 UTCEG score recompute
  24. 2026-07-22 22:51 UTCEG score recompute
  25. 2026-07-18 10:02 UTCEPSS rescore
Show 44 more
  1. 2026-07-18 10:02 UTCEPSS rescore
  2. 2026-07-04 06:29 UTCEPSS rescore
  3. 2026-07-04 06:29 UTCEPSS rescore
  4. 2026-06-27 03:06 UTCEPSS rescore
  5. 2026-06-27 03:06 UTCEPSS rescore
  6. 2026-06-25 13:48 UTCEPSS rescore
  7. 2026-06-25 13:48 UTCEPSS rescore
  8. 2026-06-22 14:24 UTCEPSS rescore
  9. 2026-06-16 17:51 UTCEPSS rescore
  10. 2026-06-16 17:51 UTCEPSS rescore
  11. 2026-06-15 17:46 UTCEPSS rescore
  12. 2026-06-13 22:58 UTCEPSS rescore
  13. 2026-06-13 22:58 UTCEPSS rescore
  14. 2026-06-12 23:10 UTCEPSS rescore
  15. 2026-06-11 13:58 UTCEPSS rescore
  16. 2026-06-11 13:58 UTCEPSS rescore
  17. 2026-06-10 22:16 UTCEPSS rescore
  18. 2026-06-10 22:16 UTCEPSS rescore
  19. 2026-06-10 13:20 UTCEPSS rescore
  20. 2026-06-07 15:23 UTCEPSS rescore
  21. 2026-06-07 15:23 UTCEPSS rescore
  22. 2026-06-05 22:45 UTCEPSS rescore
  23. 2026-06-05 06:09 UTCEPSS rescore
  24. 2026-06-05 06:09 UTCEPSS rescore
  25. 2026-06-04 13:10 UTCEPSS rescore
  26. 2026-06-04 13:10 UTCEPSS rescore
  27. 2026-06-02 20:11 UTCEPSS rescore
  28. 2026-06-02 20:11 UTCEPSS rescore
  29. 2026-06-01 13:50 UTCEPSS rescore
  30. 2026-06-01 13:50 UTCEPSS rescore
  31. 2026-05-31 22:29 UTCEPSS rescore
  32. 2026-05-31 22:29 UTCEPSS rescore
  33. 2026-05-31 00:15 UTCEPSS rescore
  34. 2026-05-31 00:15 UTCEPSS rescore
  35. 2026-05-29 13:42 UTCEPSS rescore
  36. 2026-05-28 13:43 UTCEPSS rescore
  37. 2026-05-28 13:43 UTCEPSS rescore
  38. 2026-05-27 13:39 UTCEPSS rescore
  39. 2026-05-27 13:39 UTCEPSS rescore
  40. 2026-05-26 13:42 UTCEPSS rescore
  41. 2026-05-26 13:42 UTCEPSS rescore
  42. 2026-05-26 07:46 UTCEG score recompute
  43. 2026-05-26 07:46 UTCVendor advisory
  44. 2026-05-26 07:46 UTCGHSA enrichment

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoC0xrobiul/CVE-2021-41349
    First seen Jul 30, 2022

    Microsoft Exchange Server Spoofing Vulnerability Exploit!

    Open source ↗
  • GitHub PoCexploit-io/CVE-2021-41349
    First seen Jan 6, 2022

    Exploiting: CVE-2021-41349

    Open source ↗
  • Nucleihttp/cves/2021/CVE-2021-41349.yaml
    First seen Jan 1, 2021

    Microsoft Exchange Server Pre-Auth POST Based Cross-Site Scripting

    Open source ↗

Frequently asked(5)

What is CVE-2021-41349?
CVE-2021-41349 is a critical vulnerability published on November 10, 2021. Microsoft Exchange Server Spoofing Vulnerability
When was CVE-2021-41349 disclosed?
CVE-2021-41349 was first published in the National Vulnerability Database on November 10, 2021, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-41349 actively exploited?
CVE-2021-41349 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93% probability of exploitation in the next 30 days, which ranks it in the top 0.2% of all scored CVEs.
What is the CVSS score of CVE-2021-41349?
CVE-2021-41349 has a CVSS v3 base score of 6.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
How do I remediate CVE-2021-41349?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-41349, 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-2021-41349

Explore →

Is Your Infrastructure Affected by CVE-2021-41349?

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

Start Free Scan →Browse All CVEs