CVE-2026-15557: Improper Authentication Vulnerability in waooAI waoowaoo

A significant improper authentication vulnerability, tracked as CVE-2026-15557, has been identified in waooAI waoowaoo software versions up to 0.4.1. This flaw specifically affects the getInternalTaskSession, getAuthSession, requireUserAuth, and requireProjectAuthLight functions within the src/lib/api-auth.ts library, which are part of the Internal Task Header Handler component. Attackers can exploit this by manipulating the x-internal-user-id HTTP request argument, leading to an authentication bypass. The vulnerability is remotely exploitable, meaning an attacker does not require local access to compromise affected systems. This vulnerability has been publicly disclosed, and an exploit for it is already available, significantly increasing the risk of widespread exploitation. The project developers were notified but have yet to release a patch or respond to the issue. The vulnerability has a CVSS v3.1 Base Score of 7.3 (High).

Attack Chain

1. An attacker identifies a public-facing instance of waooAI waoowaoo running a vulnerable version (up to 0.4.1).
2. The attacker crafts a malicious HTTP request targeting an application endpoint handled by the Internal Task Header Handler component.
3. This request includes a manipulated x-internal-user-id HTTP header argument.
4. The vulnerable functions (getInternalTaskSession, getAuthSession, requireUserAuth, requireProjectAuthLight) in src/lib/api-auth.ts process this manipulated argument.
5. Due to the improper authentication vulnerability, the application fails to correctly validate the request, bypassing normal authentication mechanisms.
6. The attacker gains unauthorized access to internal tasks, sessions, user, or project-related resources within the waooAI waoowaoo application.
7. This unauthorized access allows the attacker to potentially view, modify, or exfiltrate sensitive data or further compromise the system.

Impact

Successful exploitation of CVE-2026-15557 leads to an authentication bypass, granting attackers unauthorized access to resources within the waooAI waoowaoo application. This could result in data compromise, privilege escalation, and potentially further system exploitation, depending on the scope of access gained. Since the vulnerability is remotely exploitable and a public exploit is available, organizations using affected versions face an immediate and high risk of active attacks. The specific number of victims and targeted sectors are not yet detailed, but any organization utilizing waooAI waoowaoo up to version 0.4.1 is at risk.

Recommendation

• Patch CVE-2026-15557 by upgrading waooAI waoowaoo to a patched version once available.
• Deploy the Sigma rule "Detect CVE-2026-15557 Exploitation - waooAI waoowaoo Improper Authentication Attempt" to your SIEM to detect attempts to exploit this vulnerability.
• Monitor web server logs for the presence of the x-internal-user-id header in requests originating from external or unauthenticated sources, as identified in the detection rule.