CVE-2006-5973: Off-by-one buffer overflow in Dovecot 1.0test53 through 1.0.rc14, and possibly other versions, when index file

Routine

MEDIUM 5.0DOWNGRADE

CVE-2006-5973 is a medium-severity flaw (CVSS 5.0) affecting dovecot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Off-by-one buffer overflow in Dovecot 1.0test53 through 1.0.rc14, and possibly other versions, when index files are used and mmap_disable is set to "yes," allows remote authenticated IMAP or POP3 users to cause a denial of service (crash) via unspecified vectors involving the cache file.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Published	2006-11-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: timo sirainen

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

Am I affected?

Timeline

2006-11-20 19:07 UTCPublished CVE record published
2026-06-16 22:32 UTCUpdated Record last modified

timo sirainen dovecot DOWNGRADE

Affected: 1.0 · 1.0.alpha1 · 1.0.alpha2 · 1.0.alpha3 · 1.0.alpha4 · 1.0.alpha5 · 1.0.beta1 · 1.0.beta2

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison dovecot sudo apt install dovecot=<VERSION_BEFORE_1.0> sudo apt-mark hold dovecot

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

dnf --showduplicates list dovecot sudo dnf downgrade dovecot-<VERSION_BEFORE_1.0> sudo dnf versionlock add dovecot

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-2006-5973?

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

Is CVE-2006-5973 being exploited?

CVE-2006-5973 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-2006-5973 affect?

CVE-2006-5973 affects dovecot. Severity is medium (CVSS 5.0). Off-by-one buffer overflow in Dovecot 1.0test53 through 1.0.rc14, and possibly other versions, when index files are used and mmap_disable is set to "yes," allows remote authenticated IMAP or POP3 users to cause a denial of service (crash) v

How urgent is CVE-2006-5973?

Priority 39/100. No elevated risk signals yet.

Software pages

Dovecot vulnerabilities

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References

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