Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-93582— Authentication Bypass via Spoofed Remote-User Header in HTTP Basic Authentication

Quick assessment

Affected
OTRS GmbH (former OTRS AG) OTRS
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

((OTRS)) 社区版 6 及更早版本中的 HTTP 基本认证模块存在身份验证绕过漏洞。该模块会从 或 环境变量中接受经过身份验证的用户名。在基于 CGI 和 mod_perl 的部署环境中，HTTP 请求头可能会被映射到对应的 环境变量。因此，未经认证的远程攻击者可以通过提供构造的 请求头，将该值暴露为 。当 HTTP 基本认证被配置为后端认证方式时，OTRS 会信任该值作为已认证的用户名，而不再进行额外的密码验证。攻击者因此可以在不知道相应凭据的情况下，通过通用接口（Generic Interface）冒充现

CVSS 9.4 · Critical EPSS 0.39% · P31

Affected Version Matrix 7

VendorProduct Version RangeStatus
OTRS GmbH (former OTRS AG) ((OTRS)) Community Edition 6.x affected
OTRS GmbH (former OTRS AG) OTRS 7.0.x unaffected
8.0.x unaffected
2023.x unaffected
2024.x unaffected
2025.x unaffected
2026.x unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-93582

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Authentication Bypass via Spoofed Remote-User Header in HTTP Basic Authentication
Source: CVE Program / CVE List V5
Vulnerability Description
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. In CGI and mod_perl based deployments, HTTP request headers may be mapped to corresponding HTTP_* environment variables. As a result, an unauthenticated remote attacker can supply a crafted Remote-User request header which is exposed to the application as HTTP_REMOTE_USER. When HTTP Basic Authentication is configured as the authentication backend, OTRS trusts this value as an already authenticated username and does not perform an additional password verification. An attacker may therefore authenticate through the Generic Interface as an existing agent or customer user without knowing the corresponding credentials. The resulting privileges depend on the account being impersonated. Successful exploitation may allow access to confidential information and modification of data or configuration with the permissions of the affected user. Exploitation requires HTTP Basic Authentication to be configured as an authentication backend and a web server environment in which attacker-controlled HTTP headers are exposed through the corresponding HTTP_* environment variables. OTRS 7 and later are not affected by this attack vector due to the use of Mojolicious/Hypnotoad and does not expose arbitrary request headers through %ENV in the manner required for exploitation. The supported REMOTE_USER mechanism additionally requires validation through the configured SSO shared secret. The unused HTTP_REMOTE_USER fallback has nevertheless been removed as a security-hardening measure. Please note that ((OTRS)) Community Edition 6.x and before are vulnerable. Products based on the ((OTRS)) Community Edition also very likely to be affected
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
使用欺骗进行的认证绕过
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
OTRS GmbH (former OTRS AG) OTRS - -
OTRS GmbH (former OTRS AG) ((OTRS)) Community Edition 6.x -

II. Public POCs for CVE-2026-93582

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-93582

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-93582 (1)

Same Patch Batch · OTRS GmbH (former OTRS AG) · 2026-10-12 · 9 CVEs total

CVE-2026-78357 9.1 CRITICAL Insufficient Session Revocation for JWT Authentication
CVE-2026-78355 8.7 HIGH Path Traversal in SendSupportBundle allows File Deletion Outside the Intended Directory
CVE-2026-93581 6.1 MEDIUM Insufficient Neutralization of Formula Elements in CSV Exports
CVE-2026-48211 5.4 MEDIUM Cross-Site Request Forgery in Import/Export Admin console
CVE-2026-78359 5.4 MEDIUM Duplicate Identity / Identity Shadowing across CustomerUser backends
CVE-2026-78356 5.3 MEDIUM Unauthenticated Disclosure of Agent Frontend Configuration
CVE-2026-48212 4.8 MEDIUM Stored XSS in external pages
CVE-2026-78358 4.3 MEDIUM Cross-Site Request Forgery in Administrative Actions

IV. Related Vulnerabilities

Same product: OTRS
Same vendor: OTRS GmbH (former OTRS AG)
Same weakness: CWE-290

V. Comments for CVE-2026-93582

No comments yet

Leave a comment