CVE-1999-1592: Multiple unspecified vulnerabilities in sendmail 5, as installed on Sun SunOS 4.1.3_U1 and 4.1.4, have unspeci

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HIGH 7.5DOWNGRADE

CVE-1999-1592 is a high-severity flaw (CVSS 7.5) affecting sendmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple unspecified vulnerabilities in sendmail 5, as installed on Sun SunOS 4.1.3_U1 and 4.1.4, have unspecified attack vectors and impact. NOTE: this might overlap CVE-1999-0129.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	1.0% (top 37%)
CISA exploited list	No
Published	1999-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: sendmail

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

1999-12-31 05:00 UTCPublished CVE record published
2026-06-16 21:50 UTCUpdated Record last modified

sendmail sendmail DOWNGRADE

Affected: 5

Fixed in: no fixed release known

Safe to downgrade to: a release before 5

1. Check installed version

apt-cache policy sendmail || rpm -q sendmail || sendmail --version

2. No fixed release: DOWNGRADE to a release before 5 (Debian / Ubuntu)

apt-cache madison sendmail sudo apt install sendmail=<VERSION_BEFORE_5> sudo apt-mark hold sendmail

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list sendmail sudo dnf downgrade sendmail-<VERSION_BEFORE_5> sudo dnf versionlock add sendmail

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-1999-1592?

sendmail: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-1999-1592 being exploited?

CVE-1999-1592 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-1999-1592 affect?

CVE-1999-1592 affects sendmail. Severity is high (CVSS 7.5). Multiple unspecified vulnerabilities in sendmail 5, as installed on Sun SunOS 4.1.3_U1 and 4.1.4, have unspecified attack vectors and impact. NOTE: this might overlap CVE-1999-0129.

How urgent is CVE-1999-1592?

Priority 42/100. High severity

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References

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