CVE-2026-93582 OTRS GmbH (former OTRS AG) CVE debrief

Who should care

OTRS administrators, security teams, and users of ((OTRS)) Community Edition 6 and prior versions should assess exposure and take necessary actions to prevent exploitation. This includes verifying OTRS version and HTTP Basic Authentication configuration, restricting access to OTRS interfaces, and monitoring for suspicious activity. Additionally, affected operator, platform, vulnerability-management, and security-team should review and implement compensing

Why it matters

CVE-2026-93582 is a critical authentication bypass vulnerability in ((OTRS)) Community Edition 6 and prior versions. OTRS administrators and security teams should verify exposure, restrict access, and apply patches or mitigations as needed to prevent potential unauthorized access and data modification.

• Potential unauthorized access to confidential information
• Possible modification of data or configuration with affected user permissions
• Risk of lateral movement within OTRS interfaces
• Need for verification of OTRS version and HTTP Basic Authentication configuration

Technical summary

The HTTP Basic Authentication modules in ((OTRS)) Community Edition 6 and prior accept the authenticated username from either the REMOTE_USER or HTTP_REMOTE_USER environment variable. An unauthenticated remote attacker can supply a crafted Remote-User request header which is exposed to the application as HTTP_REMOTE_USER, potentially allowing impersonation of existing users. This vulnerability can be exploited when HTTP Basic Authentication is configured as an authentication backend and a web server environment in which attacker-controlled HTTP headers are mapped to environment variables. Successful exploitation may allow access to confidential information and modification of data or configuration with the of

Defensive priority

High priority for OTRS administrators and security teams to verify exposure and apply patches or mitigations.

Recommended defensive actions

• Verify OTRS version and check if HTTP Basic Authentication is configured
• Restrict access to OTRS interfaces and limit exposure
• Monitor for suspicious activity and implement compensating controls
• Apply patches or updates when available
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and potential impact. However, additional information on exploitation and remediation may be required for thorough assessment.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.