CVE-1999-0478: Denial of service in HP-UX sendmail 8.8.6 related to accepting connections.

Q: How do I fix CVE-1999-0478?

sendmail: upgrade to newer than 8.9.2. Exact commands for each OS are on this page.

Q: Is CVE-1999-0478 being exploited?

CVE-1999-0478 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-1999-0478 affect?

CVE-1999-0478 affects sendmail. Severity is medium (CVSS 5.0). Denial of service in HP-UX sendmail 8.8.6 related to accepting connections.

Q: How urgent is CVE-1999-0478?

Priority 35/100. No elevated risk signals yet.

Routine

MEDIUM 5.0UPGRADE

CVE-1999-0478 is a medium-severity flaw (CVSS 5.0) affecting sendmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Denial of service in HP-UX sendmail 8.8.6 related to accepting connections.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Published	1998-12-01
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

1998-12-01 05:00 UTCPublished CVE record published
2026-06-16 21:48 UTCUpdated Record last modified

sendmail sendmail UPGRADE

Affected: <= 8.9.2

Fixed in: newer than 8.9.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 8.9.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sendmail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sendmail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-1999-0478?

sendmail: upgrade to newer than 8.9.2. Exact commands for each OS are on this page.

Is CVE-1999-0478 being exploited?

CVE-1999-0478 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-1999-0478 affect?

CVE-1999-0478 affects sendmail. Severity is medium (CVSS 5.0). Denial of service in HP-UX sendmail 8.8.6 related to accepting connections.

How urgent is CVE-1999-0478?

Priority 35/100. No elevated risk signals yet.

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References

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