CVE-2026-34176: RCI in F5 BIG-IP
Platform
linux
Component
bigip
Fixed in
21.0.0.2
CVE-2026-34176 describes a remote command injection (RCI) vulnerability discovered in F5 BIG-IP appliances running in Appliance mode. This flaw allows an authenticated attacker to execute arbitrary commands on the system, potentially leading to complete system compromise. The vulnerability affects versions 16.1.0 through 21.0.0.2; versions past their End of Technical Support (EoTS) are not evaluated. A fix is available in version 21.0.0.2.
Impact and Attack Scenarios
Successful exploitation of CVE-2026-34176 grants an authenticated attacker the ability to execute arbitrary commands on the affected BIG-IP appliance. This could lead to a complete takeover of the system, allowing the attacker to steal sensitive data, modify configurations, or pivot to other systems within the network. The impact is particularly severe given BIG-IP's role as a critical component in many network infrastructures, often handling traffic for essential services. The ability to execute commands provides a broad attack surface, potentially enabling attackers to install malware, create backdoors, or disrupt network operations. The authentication requirement limits the immediate scope, but if an attacker can obtain valid credentials, the consequences are significant.
Exploitation Context
CVE-2026-34176 was published on May 13, 2026. Its CVSS score of 8.7 (HIGH) indicates a significant risk. Currently, there are no publicly available proof-of-concept (POC) exploits. The vulnerability is not listed on CISA KEV as of this writing, and there is no indication of active exploitation campaigns. Organizations should prioritize patching to mitigate the potential risk.
Threat Intelligence
Exploit Status
CISA SSVC
CVSS Vector
What do these metrics mean?
- Attack Vector
- Network — remotely exploitable over the internet. No physical or local access required. Widest attack surface.
- Attack Complexity
- Low — no special conditions required. Attacker can exploit reliably without depending on rare configurations or timing.
- Privileges Required
- High — admin or privileged account required to exploit.
- User Interaction
- None — attack is automatic and silent. Victim does nothing: no click, no file open.
- Scope
- Changed — successful attack can pivot beyond the vulnerable component to other systems or the host OS.
- Confidentiality
- High — complete confidentiality loss. Attacker can read all data: credentials, keys, personal data.
- Integrity
- High — attacker can write, modify, or delete any data: databases, config files, or code.
- Availability
- None — no availability impact. Service remains fully operational.
Affected Software
Weakness Classification (CWE)
Timeline
- Reserved
- Published
Mitigation and Workarounds
The primary mitigation for CVE-2026-34176 is to upgrade to F5 BIG-IP version 21.0.0.2 or later. If upgrading immediately is not feasible, consider implementing temporary workarounds. Restrict access to the vulnerable iControl REST endpoint using network segmentation and access control lists (ACLs). Implement strict authentication and authorization policies to limit the number of users with access to the iControl interface. Monitor iControl REST endpoint traffic for suspicious activity. While a WAF might offer some protection, it is not a substitute for patching. After upgrading, verify the fix by attempting to trigger the command injection vulnerability through the iControl REST endpoint and confirming that the attempt is blocked.
How to fix
F5 recomienda aplicar las actualizaciones de seguridad proporcionadas en el aviso de seguridad correspondiente (K000160857). Estas actualizaciones corrigen la vulnerabilidad de inyección de comandos remotos autenticados. Consulte la documentación oficial de F5 para obtener instrucciones detalladas sobre cómo aplicar las actualizaciones.
Frequently asked questions
What is CVE-2026-34176 — RCI in F5 BIG-IP?
CVE-2026-34176 is a remote command injection vulnerability in F5 BIG-IP appliances running in Appliance mode, allowing authenticated attackers to execute commands. It has a HIGH severity rating (8.7).
Am I affected by CVE-2026-34176 in F5 BIG-IP?
You are affected if you are running F5 BIG-IP in Appliance mode with versions between 16.1.0 and 21.0.0.2. Versions past their End of Technical Support (EoTS) are not evaluated.
How do I fix CVE-2026-34176 in F5 BIG-IP?
Upgrade to F5 BIG-IP version 21.0.0.2 or later. As a temporary workaround, restrict access to the vulnerable iControl REST endpoint and strengthen authentication.
Is CVE-2026-34176 being actively exploited?
As of now, there are no publicly available proof-of-concept exploits or reports of active exploitation campaigns, but the HIGH severity warrants immediate attention.
Where can I find the official F5 advisory for CVE-2026-34176?
Refer to the official F5 security advisory on their website for detailed information and mitigation guidance: [https://www.f5.com/security/center/advisory/f5-security-advisory-2026-34176](https://www.f5.com/security/center/advisory/f5-security-advisory-2026-34176)
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