CVE-2026-66835
Description
A flaw was found in Erlang/OTP inets httpd. A remote unauthenticated attacker can exploit a path equivalence vulnerability to bypass directory protection. By adding an extra slash to the request path, the attacker can read files within a mod_auth protected directory. This occurs because the server's path normalization does not collapse doubled slashes, leading to a mismatch in how the path is processed for authentication versus file access, ultimately resulting in information disclosure.
Mitigation
To mitigate this issue, restrict network access to the Erlang/OTP inets httpd instance to trusted clients only. Alternatively, deploy a reverse proxy in front of the inets httpd that normalizes doubled slashes in request paths before forwarding, such as configuring nginx with its default merge_slashes directive. If inets httpd is not required, consider disabling the service. If the service is active, ensure that sensitive content is served through explicitly authenticated handlers rather than relying solely on mod_auth directory-block matching.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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