CVE-2008-1836: The rfc2231 function in message.c in libclamav in ClamAV before 0.93 allows remote attackers to cause a denial

Routine

MEDIUM 4.3DOWNGRADE

CVE-2008-1836 is a medium-severity flaw (CVSS 4.3) affecting clamav. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The rfc2231 function in message.c in libclamav in ClamAV before 0.93 allows remote attackers to cause a denial of service (crash) via a crafted message that produces a string that is not null terminated, which triggers a buffer over-read.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	3.5% (top 11%)
CISA exploited list	No
Published	2008-04-16
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: clam anti-virus

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

Am I affected?

Timeline

2008-04-16 16:05 UTCPublished CVE record published
2026-06-16 22:52 UTCUpdated Record last modified

clam anti-virus clamav DOWNGRADE

Affected: 0.90 · 0.90.1 · 0.90_rc1.1 · 0.90_rc2 · 0.90_rc3 · 0.90rc1 · 0.91 · 0.92

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.90

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.90 (Debian / Ubuntu)

apt-cache madison clamav sudo apt install clamav=<VERSION_BEFORE_0.90> sudo apt-mark hold clamav

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

dnf --showduplicates list clamav sudo dnf downgrade clamav-<VERSION_BEFORE_0.90> sudo dnf versionlock add clamav

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-2008-1836?

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

Is CVE-2008-1836 being exploited?

CVE-2008-1836 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-2008-1836 affect?

CVE-2008-1836 affects clamav. Severity is medium (CVSS 4.3). The rfc2231 function in message.c in libclamav in ClamAV before 0.93 allows remote attackers to cause a denial of service (crash) via a crafted message that produces a string that is not null terminated, which triggers a buffer over-read.

How urgent is CVE-2008-1836?

Priority 37/100. No elevated risk signals yet.

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References

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