CVE-1999-0393

Exp

Remote attackers can cause a denial of service in Sendmail 8.8.x and 8.9.2 by sending messages with a large number of headers.

Published: 1999-01-01 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-1999-0393 is rated High Exploit Risk (68.6/100): CVSS Medium severity, with high exploitation likelihood (EPSS 6.03%, 90th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.02% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-1999-0393

EDB-ID Source Kind Published Link
23167 exploit_db edb 1998-12-12 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-1999-0393

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-09-27 4.01% 6.03% +2.02%
2 2025-03-30 4.07% 4.01% -0.06%
3 2025-03-29 — 4.07% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-1999-0393

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-1999-0393

OS Trackers for CVE-1999-0393

vendor priority summary link
alpine — CVE-1999-0393: no source package rows; 0 state rows across 0 repos (none); fixed 0, open 0. https://security.alpinelinux.org/vuln/CVE-1999-0393

Affected software / configurations for CVE-1999-0393

Vendor Product Version Raw CPE
eric_allman sendmail 8.8 cpe:2.3:a:eric_allman:sendmail:8.8:*:*:*:*:*:*:*
eric_allman sendmail 8.9.2 cpe:2.3:a:eric_allman:sendmail:8.9.2:*:*:*:*:*:*:*

References for CVE-1999-0393

cvelogic Threat Intelligence