External risk intelligence

Pig Authentication Bypass Vulnerability Leads to Account Takeover.

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-91995

The vulnerability exists in a user registration and password management endpoint. These features are commonly exposed via public-facing web applications to facilitate account creation and access, making this endpoint a standard component of an internet-accessible web service deployment.

Authentication Bypass

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability in the `pig` application allows an unauthenticated attacker to bypass password verification and gain administrative control by overwriting account credentials. The issue resides in the registration endpoint, where any provided value can be accepted as the current password, enabling the overwrite of any account, including administrative ones.

  • Bypass password controls to gain admin access.
  • Confirms potential for unauthorized administrative takeover.
  • Assess relevance and exposure to related systems.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by sending a request to the `/register/password` endpoint. Since the application does not properly verify the current password, any provided password will be accepted, allowing the attacker to change the credentials of any account, including administrative ones, without needing the original password. This could lead to full administrative control of the system.

  • No authentication or special access needed.
  • Submit username and new password.
  • Take over any account.

Live Threat

Current exploitation, exposure, and threat context

Remote attackers could overwrite any account credential, including the administrator account, by exploiting an authentication bypass in the password verification process on the `/register/password` endpoint. This could lead to full administrative control of the affected system when supported by the advisory.

  • User account credentials.
  • Password verification is discarded.
  • Unauthorized administrative control.

Operational Fix

Recommended remediation, mitigation, and detection steps

The critical authentication bypass in the `/register/password` endpoint suggests that platform or application owners are primarily responsible for addressing this vulnerability. The first step is to locate all instances of the affected technology, determine their exposure and criticality, and identify the accountable system owner. This will enable a risk-based remediation plan, potentially involving vendor coordination or temporary controls if immediate patching is not feasible.

  • Identify application and platform owners.
  • Verify affected technology deployment and reachability.
  • Plan remediation with vendor and system owners.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is the Pig software and how is it used?

Pig is a software framework often utilized as a foundation for building enterprise-level applications, frequently incorporating user management and administrative modules. It provides core functionality for handling identity and access, which are critical for controlling who can interact with or manage the system. Developers integrate it into web services to streamline account creation and security management tasks.

What does CWE-620 mean for CVE-2026-91995?

CWE-620 refers to an issue where a system fails to properly verify the authenticity of a password during a credential change. In the context of CVE-2026-91995, the application's verification process is fundamentally flawed because it discards the result of the password check. Because the system does not actually confirm the old password, it treats any input as valid, which allows an unauthorized person to change credentials for any account.

How can an attacker trigger this vulnerability?

An attacker triggers this by sending a specially crafted request to the specific '/register/password' endpoint. They do not need previous access or an existing session to initiate this. It is important to note that actions performed outside of this specific registration and password management workflow do not trigger this bypass. The vulnerability is strictly tied to the flawed logic within this particular endpoint's password verification routine.

Why should I care about this vulnerability based on Halo Surface Signal?

Halo Surface Signal indicates that the affected endpoint is a common feature in web applications intended for user interaction. Because these functions are typically exposed to the internet to allow for self-service account registration and password resets, your deployment is likely reachable by remote parties. If your instance is accessible via the web, you should assume the component is exposed to potential unauthorized interaction.

How do I start addressing this Pig vulnerability?

Begin by identifying every instance of Pig running in your environment to understand your total footprint. Once you have a list of deployments, determine which ones are reachable from the internet, as these represent the highest priority. Communicate with the application owners for each instance to coordinate an update, as this is a fundamental code-level issue that requires a formal patch to resolve correctly.

References