CVE-2026-51788: cleverange_auth v0.1.10 DoS Vulnerability

CVE-2026-51788 Overview

CVE-2026-51788 affects cleverange_auth version 0.1.10, a Python authentication package distributed via PyPI. The vulnerability resides in the account_verification function within the accounts/models.py component. A remote attacker can trigger a denial of service condition by abusing this function. Exploitation requires user interaction and has high attack complexity, limiting real-world impact. No confidentiality or integrity impact is associated with this issue, only availability degradation of the authentication flow.

Critical Impact

Remote attackers can disrupt account verification workflows in applications relying on cleverange_auth v0.1.10, causing availability loss for authentication services.

Affected Products

• cleverange_auth v0.1.10 (PyPI package)
• Django applications importing the vulnerable accounts/models.py module
• Deployments using the account_verification function from Cleverange Auth

Discovery Timeline

• 2026-09-01 - CVE-2026-51788 published to NVD
• 2026-09-03 - Last updated in NVD database

Technical Details for CVE-2026-51788

Vulnerability Analysis

The flaw exists in the account_verification function inside accounts/models.py of the cleverange_auth package. The function fails to handle malformed or unexpected input safely during the account verification process. When invoked with crafted parameters over the network, the function enters a state that consumes resources or terminates execution abnormally. This results in a denial of service for the authentication workflow.

The vulnerability class aligns with Denial of Service via improper input validation in an authentication routine. Because the affected code path is reachable during account verification, unauthenticated remote actors can interact with it whenever the verification endpoint is exposed.

Root Cause

The root cause is insufficient input validation within the account_verification function. The function does not properly guard against inputs that trigger resource-intensive or exception-generating code paths. Because verification tokens are typically accepted from untrusted network sources, the missing validation directly exposes the availability of the authentication component.

Attack Vector

Exploitation occurs over the network without authentication, but requires a target user to interact with an attacker-supplied verification link or payload. The complexity is high, meaning the attacker must satisfy specific preconditions such as valid endpoint state or session context. Successful exploitation blocks legitimate users from completing account verification. See the GitHub Repository for CVE-2026-51788 and the Cleverange Auth PyPI Package for artifact details.

No verified proof-of-concept code is available. The vulnerability mechanism is documented at the referenced repository.

Detection Methods for CVE-2026-51788

Indicators of Compromise

• Repeated failed calls to the account_verification endpoint from a single source or distributed set of sources
• Unhandled exceptions or crash traces referencing accounts/models.py in application logs
• Sudden spikes in latency or worker exhaustion in Django processes hosting cleverange_auth

Detection Strategies

• Inventory Python dependencies to identify installations of cleverange_auth version 0.1.10
• Instrument the account_verification function with structured logging to capture input parameters and exception traces
• Correlate web server access logs with application exception logs to detect abusive verification request patterns

Monitoring Recommendations

• Alert on elevated HTTP 5xx rates on account verification routes
• Track worker restarts, timeouts, and memory pressure on services exposing Cleverange Auth
• Monitor PyPI dependency manifests in CI/CD pipelines for the affected version

How to Mitigate CVE-2026-51788

Immediate Actions Required

• Identify all applications that depend on cleverange_auth v0.1.10 and treat their verification endpoints as at-risk
• Restrict network access to authentication endpoints where feasible, using WAF or reverse-proxy rate limiting
• Add input validation at the framework layer before requests reach account_verification

Patch Information

At the time of publication, no fixed version is listed in the NVD entry. Review the Cleverange Auth PyPI Package for newer releases and the Cleverange Auth Homepage for vendor advisories before upgrading. If a patched release is unavailable, consider replacing the dependency or forking and applying local input validation to the account_verification function.

Workarounds

• Apply rate limiting on the verification endpoint to reduce impact of repeated abuse
• Validate and sanitize verification tokens at the view layer before invoking account_verification
• Wrap calls to account_verification with defensive exception handling to prevent worker crashes
• Temporarily disable self-service account verification if the feature is not essential