How severe is CVE-2006-3121?

CVE-2006-3121 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2006-3121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-3121?

CVE-2006-3121 primarily affects High Availability Linux Project Heartbeat. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2006-3121?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2006-3121 published?

CVE-2006-3121 was published on 2006-08-17 and last updated on 2026-06-16.

CVE-2006-3121

CVE-2006-3121 is a medium-severity vulnerability in High Availability Linux Project Heartbeat with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-399.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: High Availability Linux Project Heartbeat
Published: 2006-08-17
Last modified: 2026-06-16

Description

The peel_netstring function in cl_netstring.c in the heartbeat subsystem in High-Availability Linux before 1.2.5, and 2.0 before 2.0.7, allows remote attackers to cause a denial of service (crash) via the length parameter in a heartbeat message.

Frequently asked questions

What is CVE-2006-3121?: The peel_netstring function in cl_netstring.c in the heartbeat subsystem in High-Availability Linux before 1.2.5, and 2.0 before 2.0.7, allows remote attackers to cause a denial of service (crash) via the length parameter in a heartbeat message.
How severe is CVE-2006-3121?: CVE-2006-3121 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2006-3121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-3121?: CVE-2006-3121 primarily affects High Availability Linux Project Heartbeat. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2006-3121?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-3121 published?: CVE-2006-3121 was published on 2006-08-17 and last updated on 2026-06-16.

References

Affected products (8)

cpe:2.3:a:high_availability_linux_project:heartbeat:1.2.3:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:1.2.4:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.1:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.2:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.3:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.4:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.5:*:*:*:*:*:*:*
cpe:2.3:a:high_availability_linux_project:heartbeat:2.0.6:*:*:*:*:*:*:*

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