CVE-1999-0976: Sendmail allows local users to reinitialize the aliases database via the newaliases command, then cause a deni

Routine

LOW 2.1DOWNGRADE

CVE-1999-0976 is a low-severity flaw (CVSS 2.1) affecting sendmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sendmail allows local users to reinitialize the aliases database via the newaliases command, then cause a denial of service by interrupting Sendmail.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	2.1 (Low)
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Published	1999-12-07
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: eric allman

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

Am I affected?

Timeline

1999-12-07 05:00 UTCPublished CVE record published
2026-06-16 21:49 UTCUpdated Record last modified

eric allman sendmail DOWNGRADE

Affected: 8.9.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.9.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 8.9.3 (Debian / Ubuntu)

apt-cache madison sendmail sudo apt install sendmail=<VERSION_BEFORE_8.9.3> sudo apt-mark hold sendmail

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

dnf --showduplicates list sendmail sudo dnf downgrade sendmail-<VERSION_BEFORE_8.9.3> 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-1999-0976?

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

Is CVE-1999-0976 being exploited?

CVE-1999-0976 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-1999-0976 affect?

CVE-1999-0976 affects sendmail. Severity is low (CVSS 2.1). Sendmail allows local users to reinitialize the aliases database via the newaliases command, then cause a denial of service by interrupting Sendmail.

How urgent is CVE-1999-0976?

Priority 13/100. No elevated risk signals yet.

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References

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