CVE-2008-0859: Unspecified vulnerability in Kerio MailServer before 6.5.0 allows remote attackers to cause a denial of servic

Routine

MEDIUM 5.0DOWNGRADE

CVE-2008-0859 is a medium-severity flaw (CVSS 5.0) affecting kerio mailserver. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Unspecified vulnerability in Kerio MailServer before 6.5.0 allows remote attackers to cause a denial of service (crash) via unspecified vectors related to decoding of uuencoded input, which triggers memory corruption.

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	1.4% (top 27%)
CISA exploited list	No
Weakness	CWE-399
Published	2008-02-21
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: kerio

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

Am I affected?

Timeline

2008-02-21 00:44 UTCPublished CVE record published
2026-06-16 22:50 UTCUpdated Record last modified

kerio kerio mailserver DOWNGRADE

Affected: 5.0 · 5.1 · 5.1.1 · 5.6.3 · 5.6.4 · 5.6.5 · 5.7.0 · 5.7.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0

1. Check installed version

apt-cache policy kerio-mailserver || rpm -q kerio-mailserver || kerio-mailserver --version

2. No fixed release: DOWNGRADE to a release before 5.0 (Debian / Ubuntu)

apt-cache madison kerio-mailserver sudo apt install kerio-mailserver=<VERSION_BEFORE_5.0> sudo apt-mark hold kerio-mailserver

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

dnf --showduplicates list kerio-mailserver sudo dnf downgrade kerio-mailserver-<VERSION_BEFORE_5.0> sudo dnf versionlock add kerio-mailserver

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-2008-0859?

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

Is CVE-2008-0859 being exploited?

CVE-2008-0859 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-2008-0859 affect?

CVE-2008-0859 affects kerio mailserver. Severity is medium (CVSS 5.0). Unspecified vulnerability in Kerio MailServer before 6.5.0 allows remote attackers to cause a denial of service (crash) via unspecified vectors related to decoding of uuencoded input, which triggers memory corruption.

How urgent is CVE-2008-0859?

Priority 36/100. No elevated risk signals yet.

Related CVEs

CVE-2011-1506 MEDIUM 6.8 DOWNGRADE DOWNGRADE The STARTTLS implementation in Kerio Connect 7.1.4 build 2985 and MailServer 6.x does not properly restrict I/
CVE-2009-2636 MEDIUM 4.3 DOWNGRADE Cross-site scripting (XSS) vulnerability in the Integration page in the WebMail component in Kerio MailServer
CVE-2008-5769 MEDIUM 4.3 UPGRADE Multiple cross-site scripting (XSS) vulnerabilities in Kerio MailServer before 6.6.2 allow remote attackers to
CVE-2008-5760 MEDIUM 4.3 UPGRADE Cross-site scripting (XSS) vulnerability in error413.php in Kerio MailServer before 6.6.2 allows remote attack
CVE-2008-0860 HIGH 10.0 MITIGATE UPGRADE Unspecified vulnerability in the AVG plugin in Kerio MailServer before 6.5.0 has unspecified impact via unknow

References

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