CVE-2026-76595

Description

A flaw was found in advisor-backend. Multiple code paths within the application deserialize YAML (YAML Ain't Markup Language) with an unsafe full Loader, which can instantiate arbitrary Python objects via YAML tags. An unauthenticated remote attacker can exploit this by submitting specially crafted YAML input, leading to remote code execution (RCE) within the advisor-backend pod. This compromise could allow access to shared database credentials and impact all tenants.

Statement

This Critical vulnerability in Red Hat Insights advisor-backend enables unauthenticated remote code execution. An attacker can exploit an unsafe YAML deserialization flaw, chained with an unauthenticated content import path, to execute arbitrary code within the multi-tenant advisor-backend pod. This allows for compromise of shared database credentials and tenant data, justifying the Critical impact due to the unauthenticated RCE.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Understanding the Weakness (CWE)

CWE-502

Integrity

Technical Impact: Modify Application Data; Unexpected State

Attackers can modify unexpected objects or data that was assumed to be safe from modification. Deserialized data or code could be modified without using the provided accessor functions, or unexpected functions could be invoked.

Availability

Technical Impact: DoS: Resource Consumption (CPU)

If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.

Other

Technical Impact: Varies by Context

The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation. One example is attackers using gadget chains to perform unauthorized actions, such as generating a shell.

Frequently Asked Questions

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