Is CVE-2003-0540 in the CISA KEV catalog?

No. CVE-2003-0540 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2003-0540?

CVE-2003-0540 has a CVSS v2 base score of 5.0 (MEDIUM).

What is the EPSS score for CVE-2003-0540?

CVE-2003-0540 has an EPSS score of 21.26% (97th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2003-0540

MEDIUMEPSS 97th pctl

5.0

CVSS v2

NVD

Description

The address parser code in Postfix 1.1.12 and earlier allows remote attackers to cause a denial of service (lock) via (1) a malformed envelope address to a local host that would generate a bounce and contains the ".!" string in the MAIL FROM or Errors-To headers, which causes nqmgr to lock up, or (2) via a valid MAIL FROM with a RCPT TO containing a ".!" string, which causes an instance of the SMTP listener to lock up.

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

21.26%probability of exploitation in 30 days

97thpercentile

Very high risk: more likely to be exploited than 97% of all known CVEs.

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-16.