CVE-2026-32993: HTTP Header Injection in cPanel
Platform
cpanel
Component
cpanel
Fixed in
11.136.1.12
CVE-2026-32993 is a high-severity vulnerability affecting cPanel versions 11.132.0.0 through 11.136.1.12. This vulnerability stems from improper input sanitization within the /unprotected/nova_error endpoint, allowing an unauthenticated attacker to inject arbitrary HTTP headers into the server's response. Successful exploitation could lead to redirection attacks or other malicious actions, compromising the integrity of the web server and potentially impacting hosted websites.
Impact and Attack Scenarios
The impact of CVE-2026-32993 is significant due to its unauthenticated nature and the potential for HTTP header injection. An attacker could leverage this vulnerability to redirect users to malicious websites (phishing), inject tracking headers for data exfiltration, or even modify the server's behavior by manipulating response headers. This could lead to credential theft, malware distribution, or defacement of hosted websites. The lack of authentication lowers the barrier to entry, making it accessible to a wider range of attackers. The /unprotected/nova_error endpoint is often overlooked in security assessments, making this a particularly concerning vulnerability.
Exploitation Context
CVE-2026-32993 was published on May 13, 2026. Its severity is rated HIGH (CVSS 8.3). Currently, there are no publicly known active campaigns exploiting this vulnerability. No KEV or EPSS score is available at this time. Monitor security advisories and threat intelligence feeds for any indications of exploitation.
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
- None — unauthenticated. No login or credentials needed 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
- Low — partial or indirect data access. Attacker gains limited information.
- Integrity
- Low — attacker can modify some data with limited scope or impact.
- Availability
- Low — partial or intermittent denial of service. Attacker can degrade performance.
Affected Software
Weakness Classification (CWE)
Timeline
- Reserved
- Published
- Modified
Mitigation and Workarounds
The primary mitigation for CVE-2026-32993 is to upgrade cPanel to version 11.136.1.12 or later, which contains the necessary fix. If immediate upgrade is not possible, consider implementing a Web Application Firewall (WAF) rule to block requests containing suspicious characters or patterns in the status query parameter of the /unprotected/novaerror endpoint. Alternatively, restrict access to the /unprotected/novaerror endpoint to trusted networks or IP addresses. Thoroughly review and harden cPanel's configuration, ensuring that all unnecessary features and endpoints are disabled. After upgrading, confirm the fix by attempting to inject a custom HTTP header via the /unprotected/nova_error endpoint; the request should be rejected.
How to fix
Actualice cPanel a la versión 11.132.0.32 o posterior, 11.134.0.26 o posterior, 11.136.0.10 o posterior, o 11.136.1.12 o posterior para mitigar la vulnerabilidad. La actualización corrige la falta de sanitización adecuada del parámetro de consulta 'status' en el endpoint '/unprotected/nova_error', previniendo la inyección de encabezados HTTP arbitrarios.
Frequently asked questions
What is CVE-2026-32993 — HTTP Header Injection in cPanel?
CVE-2026-32993 is a high-severity vulnerability in cPanel versions 11.132.0.0–11.136.1.12 that allows unauthenticated attackers to inject arbitrary HTTP headers via the /unprotected/nova_error endpoint, potentially leading to redirection or data exfiltration.
Am I affected by CVE-2026-32993 in cPanel?
You are affected if you are running cPanel versions 11.132.0.0 through 11.136.1.12. Check your cPanel version using /usr/local/cpanel/cpversion.
How do I fix CVE-2026-32993 in cPanel?
Upgrade cPanel to version 11.136.1.12 or later. As a temporary workaround, implement a WAF rule to block suspicious requests to the /unprotected/nova_error endpoint.
Is CVE-2026-32993 being actively exploited?
Currently, there are no publicly known active campaigns exploiting CVE-2026-32993, but it's crucial to apply the patch promptly.
Where can I find the official cPanel advisory for CVE-2026-32993?
Refer to the official cPanel security advisory for CVE-2026-32993 on the cPanel website (https://security.cpanel.net/ - search for CVE-2026-32993).
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