CVE-2026-76994: Apache Answer Information Disclosure Flaw

CVE-2026-76994 Overview

CVE-2026-76994 is an information disclosure vulnerability in Apache Answer, an open-source Q&A platform. The flaw allows unauthenticated attackers to retrieve metadata associated with hidden questions by querying public answer profiles. Apache Answer versions through 2.0.2 are affected, and version 2.0.3 contains the fix. The weakness is categorized under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor).

Critical Impact
Remote unauthenticated attackers can enumerate metadata of hidden questions through public answer profile endpoints, defeating the privacy controls intended for hidden content.

Affected Products

Apache Answer versions through 2.0.2
Public answer profile endpoints exposing hidden question metadata
Deployments relying on question hiding for content privacy

Discovery Timeline

2026-10-19 - CVE CVE-2026-76994 published to NVD
2026-10-19 - Last updated in NVD database

Technical Details for CVE-2026-76994

Vulnerability Analysis

Apache Answer provides a mechanism for administrators and users to hide questions from public listings. The platform exposes user answer profiles that aggregate the answers a user has posted. The profile endpoints return metadata referencing hidden questions without enforcing the same visibility checks applied to the question listing itself.

An unauthenticated attacker can enumerate user profiles and extract metadata describing hidden questions, including identifiers and other associated attributes. This defeats the intended confidentiality boundary of the hidden-question feature. The scope of exposure is limited to metadata rather than full question bodies, but it is sufficient to catalogue hidden content and target follow-on actions.

Root Cause

The root cause is missing or inconsistent authorization enforcement on the public answer profile path. The question-visibility check applied when listing questions is not propagated to the profile view that references those same questions, leaving metadata reachable through an alternate access path.

Attack Vector

Exploitation requires no authentication and no user interaction. An attacker issues HTTP requests to the public answer profile endpoint of any user who has answered a hidden question, then parses the response for the referenced question metadata. The attack is network-reachable against any internet-exposed Apache Answer instance running an affected version. Technical specifics are documented in the Apache Security Mailing List Thread and the OpenWall OSS-Security Update.

Detection Methods for CVE-2026-76994

Indicators of Compromise

Unauthenticated HTTP GET requests to /users/*/answers or equivalent profile endpoints from a single source at scale
Spikes in anonymous traffic enumerating user profiles in short time windows
Server logs showing profile responses that reference question identifiers absent from the public question index

Detection Strategies

Compare question identifiers returned by profile endpoints against the public question listing and alert on identifiers marked hidden
Rate-limit and baseline anonymous access to user profile routes to detect enumeration behavior
Review web application firewall (WAF) logs for sequential user-ID or username iteration patterns

Monitoring Recommendations

Enable verbose access logging on Apache Answer front-end routes and ship logs to a centralized SIEM
Monitor for user-agent strings and IP addresses performing bulk profile retrieval
Alert on any crawler activity touching profile endpoints without an authenticated session cookie

How to Mitigate CVE-2026-76994

Immediate Actions Required

Upgrade Apache Answer to version 2.0.3 or later, which contains the authorization fix
Audit existing hidden questions and treat their metadata as potentially disclosed until the upgrade is confirmed
Restrict anonymous access to profile endpoints at the reverse proxy layer until patching is complete

Patch Information

The Apache Answer project resolved the issue in version 2.0.3. Administrators should upgrade directly to this release. Confirmation and release details are available in the Apache Security Mailing List Thread.

Workarounds

Place Apache Answer behind an authenticated reverse proxy to block unauthenticated profile enumeration
Apply WAF rules that rate-limit or require authentication on /users/*/answers and similar profile paths
Temporarily disable public answer profiles if the deployment permits, pending the upgrade to 2.0.3

bash

# Example nginx rule to require authentication on profile endpoints
location ~ ^/users/.+/answers {
    auth_request /auth;
    limit_req zone=profile burst=5 nodelay;
    proxy_pass http://answer_backend;
}