How severe is CVE-2015-4638?

CVE-2015-4638 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2015-4638 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-4638?

CVE-2015-4638 primarily affects F5 Big-ip Advanced Firewall Manager. In total, 57 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-4638?

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

When was CVE-2015-4638 published?

CVE-2015-4638 was published on 2015-09-18 and last updated on 2026-06-17.

CVE-2015-4638

CVE-2015-4638 is a medium-severity vulnerability in F5 Big-ip Advanced Firewall Manager with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: F5 Big-ip Advanced Firewall Manager
Published: 2015-09-18
Last modified: 2026-06-17

Description

The FastL4 virtual server in F5 BIG-IP LTM, AAM, AFM, Analytics, APM, ASM, GTM, Link Controller, and PEM 11.3.0 through 11.5.2 and 11.6.0 through 11.6.0 HF4, BIG-IP Edge Gateway, WebAccelerator, and WOM 11.2.1 through 11.3.0, and BIG-IP PSM 11.2.1 through 11.4.1 allows remote attackers to cause a denial of service (Traffic Management Microkernel restart) via a fragmented packet.

Frequently asked questions

What is CVE-2015-4638?: The FastL4 virtual server in F5 BIG-IP LTM, AAM, AFM, Analytics, APM, ASM, GTM, Link Controller, and PEM 11.3.0 through 11.5.2 and 11.6.0 through 11.6.0 HF4, BIG-IP Edge Gateway, WebAccelerator, and WOM 11.2.1 through 11.3.0, and BIG-IP PSM 11.2.1 through 11.4.1 allows remote attackers to cause a denial of service (Traffic Management Microkernel restart) via a fragmented packet.
How severe is CVE-2015-4638?: CVE-2015-4638 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2015-4638 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-4638?: CVE-2015-4638 primarily affects F5 Big-ip Advanced Firewall Manager. In total, 57 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-4638?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-4638 published?: CVE-2015-4638 was published on 2015-09-18 and last updated on 2026-06-17.

References

Affected products (57)

cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.4.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.2:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.6.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.4.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.5.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.5.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.5.2:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:11.6.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.4.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.5.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.5.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.5.2:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:11.6.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_edge_gateway:11.2.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_edge_gateway:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.4.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.2:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:11.6.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.4.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.5.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.5.1:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.5.2:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:11.6.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:11.3.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:11.4.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:11.4.1:*:*:*:*:*:*:*

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