CVE-2001-0653: Sendmail 8.10.0 through 8.11.5, and 8.12.0 beta, allows local users to modify process memory and possibly gain

Routine

MEDIUM 4.6DOWNGRADE

CVE-2001-0653 is a medium-severity flaw (CVSS 4.6) affecting sendmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sendmail 8.10.0 through 8.11.5, and 8.12.0 beta, allows local users to modify process memory and possibly gain privileges via a large value in the 'category' part of debugger (-d) command line arguments, which is interpreted as a negative number.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	4.6 (Medium)
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Published	2001-09-20
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

2001-09-20 04:00 UTCPublished CVE record published
2026-06-16 21:54 UTCUpdated Record last modified

sendmail sendmail DOWNGRADE

Affected: 8.11.0 · 8.11.1 · 8.11.2 · 8.11.3 · 8.11.4 · 8.11.5 · 8.12 beta10 · 8.12 beta12

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.11.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 8.11.0 (Debian / Ubuntu)

apt-cache madison sendmail sudo apt install sendmail=<VERSION_BEFORE_8.11.0> sudo apt-mark hold sendmail

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

dnf --showduplicates list sendmail sudo dnf downgrade sendmail-<VERSION_BEFORE_8.11.0> 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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Sendmail 8.11/8.12 Debugger - Arbitrary Code Execution (1)
Exploit-DB: Sendmail 8.11/8.12 Debugger - Arbitrary Code Execution (2)
Exploit-DB: Sendmail 8.11/8.12 Debugger - Arbitrary Code Execution (3)
Exploit-DB: Sendmail 8.11/8.12 Debugger - Arbitrary Code Execution (4)

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-2001-0653?

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

Is CVE-2001-0653 being exploited?

CVE-2001-0653 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-2001-0653 affect?

CVE-2001-0653 affects sendmail. Severity is medium (CVSS 4.6). Sendmail 8.10.0 through 8.11.5, and 8.12.0 beta, allows local users to modify process memory and possibly gain privileges via a large value in the 'category' part of debugger (-d) command line arguments, which is interpreted as a negative n

How urgent is CVE-2001-0653?

Priority 38/100. Public exploit reference

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References

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