CVE-2021-40900
CVSS v3
7.5
HIGH
EPSS Score
1.1 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in regexfn v1.0.5 when validating crafted invalid emails.
Technical details
- Published
- 2022-06-27
Frequently asked questions
What is CVE-2021-40900?
A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in regexfn v1.0.5 when validating crafted invalid emails.
Is CVE-2021-40900 actively exploited?
Active exploitation of CVE-2021-40900 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-40900?
CVE-2021-40900 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-40900 affecting your environment?
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