CVE-2021-31988

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

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

A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to add the Carriage Return and Line Feed (CRLF) control characters and include arbitrary SMTP headers in the generated test email.

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
56.2%
KEV
Not listed

Published

October 5, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 43× 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. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-11 08:25 UTCEPSS rescore
  3. 2026-07-09 19:07 UTCEPSS rescore
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  22. 2026-06-24 14:03 UTCEPSS rescore
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  24. 2026-06-23 21:31 UTCEPSS rescore
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  1. 2026-06-22 14:24 UTCEPSS rescore
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  3. 2026-06-21 14:55 UTCEPSS rescore
  4. 2026-06-21 01:58 UTCEPSS rescore
  5. 2026-06-21 01:58 UTCEPSS rescore
  6. 2026-06-19 19:24 UTCEPSS rescore
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  8. 2026-06-18 17:51 UTCEPSS rescore
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  17. 2026-06-12 23:10 UTCEPSS rescore
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  19. 2026-06-11 13:58 UTCEPSS rescore
  20. 2026-06-10 22:16 UTCEPSS rescore
  21. 2026-06-10 13:20 UTCEPSS rescore
  22. 2026-06-08 14:15 UTCEPSS rescore
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  24. 2026-06-07 15:23 UTCEPSS rescore
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  26. 2026-06-06 13:46 UTCEPSS rescore
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  30. 2026-06-05 06:09 UTCEPSS rescore
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  36. 2026-06-01 13:50 UTCEPSS rescore
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  38. 2026-05-31 22:29 UTCEPSS rescore
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  40. 2026-05-31 00:15 UTCEPSS rescore
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  42. 2026-05-29 13:42 UTCEPSS rescore
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  44. 2026-05-28 13:43 UTCEPSS rescore
  45. 2026-05-28 13:43 UTCEPSS rescore
  46. 2026-05-27 13:39 UTCEPSS rescore
  47. 2026-05-27 13:39 UTCEPSS rescore
  48. 2026-05-27 13:39 UTCEPSS rescore
  49. 2026-05-26 13:42 UTCEPSS rescore
  50. 2026-05-26 09:28 UTCEG score recompute
  51. 2026-05-26 09:28 UTCGHSA enrichment
  52. 2026-05-26 07:17 UTCEPSS rescore
  53. 2026-05-26 07:17 UTCEPSS rescore
  54. 2026-05-26 07:17 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-31988?
CVE-2021-31988 is a high vulnerability published on October 5, 2021. A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to add the Carriage Return and Line Feed (CRLF) control characters and include arbitrary SMTP headers in the generated test email.
When was CVE-2021-31988 disclosed?
CVE-2021-31988 was first published in the National Vulnerability Database on October 5, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-31988 actively exploited?
CVE-2021-31988 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-31988?
CVE-2021-31988 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-31988?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-31988, 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.

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