How severe is CVE-2023-40534?

CVE-2023-40534 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-40534 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-40534?

CVE-2023-40534 primarily affects F5 Big-ip Access Policy Manager. In total, 39 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-40534?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-40534 published?

CVE-2023-40534 was published on 2023-10-10 and last updated on 2026-06-17.

CVE-2023-40534

CVE-2023-40534 is a high-severity vulnerability in F5 Big-ip Access Policy Manager with a CVSS 3.x base score of 7.5. 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-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: F5 Big-ip Access Policy Manager
Published: 2023-10-10
Last modified: 2026-06-17

Description

When a client-side HTTP/2 profile and the HTTP MRF Router option are enabled for a virtual server, and an iRule using the HTTP_REQUEST event or Local Traffic Policy are associated with the virtual server, undisclosed requests can cause TMM to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2023-40534?: When a client-side HTTP/2 profile and the HTTP MRF Router option are enabled for a virtual server, and an iRule using the HTTP_REQUEST event or Local Traffic Policy are associated with the virtual server, undisclosed requests can cause TMM to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2023-40534?: CVE-2023-40534 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-40534 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-40534?: CVE-2023-40534 primarily affects F5 Big-ip Access Policy Manager. In total, 39 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-40534?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-40534 published?: CVE-2023-40534 was published on 2023-10-10 and last updated on 2026-06-17.

References

https://my.f5.com/manage/s/article/K000133467

Affected products (39)

cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_access_policy_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_firewall_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_analytics:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_acceleration_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_security_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_visibility_and_reporting:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_application_visibility_and_reporting:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_carrier-grade_nat:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_carrier-grade_nat:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ddos_hybrid_defender:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ddos_hybrid_defender:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_domain_name_system:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_edge_gateway:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_fraud_protection_service:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_global_traffic_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_link_controller:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_local_traffic_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_next_service_proxy_for_kubernetes:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_policy_enforcement_manager:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ssl_orchestrator:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_ssl_orchestrator:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_webaccelerator:17.1.0:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_websafe:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:big-ip_websafe:17.1.0:*:*:*:*:*:*:*

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