CVE-2026-67598: Emlog Pro Information Disclosure Flaw

CVE-2026-67598 Overview

CVE-2026-67598 affects Emlog Pro through version 2.6.23. The vulnerability resides in include/service/ai.php, where TLS certificate validation is unconditionally disabled for outbound HTTPS requests to configured Large Language Model (LLM) providers. The CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options are turned off across sendStream(), sendImageRequest(), send(), and fetchSearchHtml(), with no configuration option to re-enable verification. Network-adjacent attackers can present arbitrary TLS certificates to intercept traffic, extract Authorization Bearer API keys, and inject crafted AI responses. The issue is classified under CWE-295 (Improper Certificate Validation).

Critical Impact
Man-in-the-middle attackers can steal LLM provider API keys and inject malicious AI responses processed by tool-call handlers such as query_database and update_config.

Affected Products

Emlog Pro through version 2.6.23
include/service/ai.php service module
Deployments configured with LLM provider integrations

Discovery Timeline

2026-08-03 - CVE-2026-67598 published to NVD
2026-08-04 - Last updated in NVD database

Technical Details for CVE-2026-67598

Vulnerability Analysis

Emlog Pro integrates with external LLM providers through the AI service module. The module uses PHP's cURL extension to issue outbound HTTPS requests. In every request path, the code sets CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST to false. This disables both peer certificate chain validation and hostname verification.

The disabled verification is applied unconditionally. There is no administrative toggle, configuration flag, or environment check that permits re-enabling verification. As a result, the client accepts any TLS certificate presented by the endpoint it connects to, including self-signed certificates issued by an attacker on the network path.

The consequences extend beyond credential theft. Emlog Pro processes AI responses through a tool-call execution pipeline that includes handlers such as query_database and update_config. An attacker who intercepts and rewrites the response body can direct the application to run attacker-chosen tool invocations against the site's own database and configuration state.

Root Cause

The root cause is improper certificate validation [CWE-295]. The developer disabled TLS verification, most likely to avoid certificate errors during development, and shipped that configuration in production code paths. No fallback verification, certificate pinning, or trust-store selection is present.

Attack Vector

Exploitation requires a network-adjacent position between the Emlog Pro server and the configured LLM provider. This includes compromised upstream routers, malicious Wi-Fi infrastructure, hostile Internet Service Providers (ISPs), or DNS hijacks that redirect the provider hostname. Once positioned, the attacker terminates the TLS connection with a self-signed certificate, reads the Authorization Bearer token from the request headers, and forwards or fabricates a response. The Emlog Pro AI response parser then hands the attacker-controlled content to its tool-call executor.

The vulnerability is described in the GitHub Security Advisory and the VulnCheck Security Advisory.

Detection Methods for CVE-2026-67598

Indicators of Compromise

Outbound HTTPS connections from Emlog Pro servers to LLM provider hostnames that terminate at unexpected IP addresses or autonomous system numbers.
TLS handshakes to LLM endpoints presenting self-signed or non-provider-issued certificates.
Unexpected query_database or update_config tool invocations in Emlog Pro logs following AI-assisted operations.
Sudden invalidation or rotation events on LLM provider API keys used by Emlog Pro.

Detection Strategies

Static code review of include/service/ai.php for CURLOPT_SSL_VERIFYPEER or CURLOPT_SSL_VERIFYHOST set to false or 0.
Egress TLS inspection that flags certificate subjects not matching pinned LLM provider certificate authorities.
Application log correlation between AI response parsing events and subsequent database or configuration write operations.

Monitoring Recommendations

Alert on any change to Emlog Pro configuration tables that follows an AI request within a short time window.
Monitor for anomalous outbound destinations resolving to the configured LLM provider hostname.
Track LLM provider account usage from a separate, out-of-band channel to detect unauthorized key reuse.

How to Mitigate CVE-2026-67598

Immediate Actions Required

Rotate every LLM provider API key configured in Emlog Pro, since prior traffic may have exposed them.
Disable the AI integration until a patched version is deployed if Emlog Pro is reachable over untrusted network paths.
Restrict egress from the Emlog Pro host to known LLM provider IP ranges through firewall rules.
Review recent query_database and update_config tool invocations for unauthorized activity.

Patch Information

No vendor-fixed version is listed in the enriched CVE data at time of publication. Refer to the Emlog GitHub Security Advisory for the most current remediation status and any subsequent release that restores certificate validation.

Workarounds

Patch include/service/ai.php locally to set CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST to true across sendStream(), sendImageRequest(), send(), and fetchSearchHtml().
Route outbound LLM traffic through a trusted forward proxy that enforces certificate validation and pins the provider certificate authority.
Isolate the Emlog Pro server on a network segment where the path to the LLM provider cannot be intercepted by untrusted parties.

bash

# Example manual hardening in include/service/ai.php
# Replace disabled verification with enforced checks
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_CAINFO, '/etc/ssl/certs/ca-certificates.crt');