CVE-2026-49949: CodexBar Credential Forwarding Vulnerability (CVSS 5.3)

Technical summary

CVE-2026-49949 is a credential forwarding vulnerability in CodexBar's ProviderHTTPClient transport layer. The flaw allows network-adjacent attackers to intercept authenticated provider requests by injecting cross-origin or HTTP-downgrade redirects. When the vulnerable HTTP client follows these redirects without properly isolating credential scope, session tokens and API keys intended for legitimate service endpoints are leaked to attacker-controlled locations. The vulnerability is classified under CWE-522 (Inadequately Protected Credentials), with a CVSS 3.1 score of 5.3 (Medium severity). Exploitation requires network adjacency and user interaction but results in high confidentiality impact with no integrity or availability consequences.

Business impact

Compromise of bearer tokens, API keys, and session cookies used by CodexBar can lead to unauthorized access to downstream services and data stores that trust those credentials. The blast radius depends on the privilege level and scope of compromised tokens; a leaked API key with broad permissions could enable attackers to exfiltrate sensitive data or pivot into connected systems. Organizations should assume that any credentials transited through vulnerable CodexBar instances may be exposed and should consider rotation and access revocation as part of their incident response.

Affected systems

CodexBar versions prior to 0.33.0 are affected. The vulnerability resides in the shared ProviderHTTPClient transport used for authenticated API calls. Any deployment of CodexBar in which provider requests carry sensitive credentials—especially in multi-tenant or shared network environments—is at risk. Deployments isolated from untrusted networks may face reduced practical risk, but credential leakage is still possible if an attacker achieves network adjacency through routing tricks or physical positioning.

Exploitability

Exploitation is feasible but requires two conditions: network adjacency to the target and user interaction (such as the user clicking a link or the application following an attacker-controlled redirect). The CVSS vector (AV:N/AC:H) reflects that while network access is possible, the attack complexity is high. An attacker must craft a precise redirect scenario and position themselves on the network path or have the ability to influence DNS/routing. In isolated internal environments, the practical risk is lower; in cloud or shared-network scenarios, it is higher. No public exploit code or KEV listing exists as of the advisory date.

Remediation

Upgrade CodexBar to version 0.33.0 or later immediately. The patched version corrects the credential forwarding flaw by enforcing strict credential scope validation during redirect handling and preventing HTTP downgrade attacks. Organizations should also rotate any credentials (API keys, bearer tokens, session cookies) that were active on vulnerable instances during the suspected exposure window, and review access logs from downstream services for unusual activity.

Patch guidance

Apply CodexBar 0.33.0 or a later stable release as soon as possible. Verify the patch in your vendor advisory to confirm version numbers and any additional configuration changes required. If you cannot upgrade immediately, consider network segmentation to limit attacker proximity, implement strict outbound redirect policies in your HTTP client configuration if available, and monitor for suspicious cross-origin or HTTP downgrade activity in your logs. Test patches in a non-production environment first to ensure compatibility with your deployment.

Detection guidance

Monitor CodexBar HTTP traffic for unusual redirect sequences, especially cross-origin redirects or HTTP-to-HTTPS downgrade scenarios. Check application logs for redirect responses (301, 302, 307, 308) pointing to unexpected hosts or plaintext HTTP endpoints. Review credential usage in downstream services for anomalous patterns (new IP sources, unexpected token usage, API key activity outside normal schedules). If you have flow visibility, look for CodexBar initiating connections to attacker-controlled IPs or domains following credential-bearing requests. Implement alerting on redirect chains that cross security boundaries.

Why prioritize this

Although this is a Medium-severity vulnerability with a CVSS score of 5.3, it poses a direct credential compromise risk that could unlock unauthorized access to backend systems. The requirement for network adjacency and user interaction lowers urgency slightly, but organizations handling sensitive data or relying on strict API key isolation should treat this as a near-term patch priority. Credential leakage has compounding effects; even a single compromised token can cascade into broader system compromise if not quickly detected and revoked.

Risk score, explained

The CVSS 3.1 score of 5.3 (Medium) reflects high confidentiality impact (C:H) offset by high attack complexity (AC:H) and the need for user interaction (UI:R). Network adjacency (AV:N) is required, and the scope is unchanged (S:U). No integrity or availability impact is noted. The score appropriately captures that while the potential harm (credential theft) is serious, the practical barriers to exploitation—network position and user action—limit the overall severity rating. In high-trust or network-isolated environments, the practical risk may be lower; in shared or cloud-native architectures, it may be higher.

Frequently asked questions