CVE-2026-28677: OpenSift AI Study Tool SSRF Vulnerability

CVE-2026-28677 Overview

CVE-2026-28677 is a Server-Side Request Forgery (SSRF) vulnerability in OpenSift, an AI study tool that processes large datasets using semantic search and generative AI. The vulnerability exists in the URL ingest pipeline, which accepted user-controlled remote URLs with incomplete destination restrictions. Although the application implemented private/local host checks, missing restrictions for credentialed URLs, non-standard ports, and cross-host redirects left SSRF-class abuse paths in non-localhost deployments.

Critical Impact

Attackers can exploit the incomplete URL validation to perform unauthorized requests to internal services, potentially accessing sensitive data, cloud metadata endpoints, or internal infrastructure not meant to be publicly accessible.

Affected Products

• OpenSift versions prior to 1.6.3-alpha

Discovery Timeline

• 2026-03-06 - CVE-2026-28677 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-28677

Vulnerability Analysis

This SSRF vulnerability (CWE-918) allows attackers to manipulate the URL ingest functionality to make server-side requests to arbitrary destinations. The root issue stems from incomplete URL validation that failed to account for several bypass techniques commonly used in SSRF attacks.

The existing security controls only validated against private/local hostname patterns but did not restrict embedded credentials in URLs (e.g., http://user:pass@internal-host/), non-standard ports that could target internal services, or redirect chains that could bounce requests through trusted hosts to reach internal targets.

In non-localhost deployments, this creates significant risk as attackers could leverage the application server to probe internal networks, access cloud provider metadata services (such as AWS IMDSv1 at 169.254.169.254), or interact with internal APIs and databases.

Root Cause

The vulnerability originates from incomplete input validation in the URL ingest pipeline. While the application checked for private/local hostnames, it failed to implement comprehensive URL validation covering all SSRF bypass vectors including credentialed URLs, non-standard port access, and redirect-based attacks.

Attack Vector

An attacker could exploit this vulnerability by submitting crafted URLs to the ingest pipeline. Example attack vectors include:

1. Credentialed URLs: Submitting URLs with embedded credentials to bypass hostname checks
2. Non-standard ports: Targeting internal services on ports other than 80/443
3. Redirect chains: Using open redirects on trusted hosts to reach internal targets

The security patch adds validation for these missing cases:

        raise RuntimeError("Only http/https URLs are allowed.")
    if not parsed.hostname:
        raise RuntimeError("URL must include a hostname.")
+    if parsed.username or parsed.password:
+        raise RuntimeError("URLs with embedded credentials are not allowed.")
+    if parsed.port and parsed.port not in (80, 443):
+        raise RuntimeError("Only standard ports 80/443 are allowed for URL ingest.")
    if _is_blocked_host_label(parsed.hostname):
        raise RuntimeError("Local hostnames are blocked for URL ingest.")

Source: GitHub Commit 1126e0a

Detection Methods for CVE-2026-28677

Indicators of Compromise

• Unusual outbound requests from the OpenSift application server to internal IP ranges (10.x.x.x, 172.16.x.x, 192.168.x.x)
• URL ingest requests containing embedded credentials (username:password@ format)
• Requests to cloud metadata endpoints (169.254.169.254) originating from the application
• HTTP requests to non-standard ports from the ingest pipeline

Detection Strategies

• Monitor application logs for URL ingest requests containing credential patterns or non-standard ports
• Implement network-level detection for SSRF patterns, including requests to RFC1918 addresses from web application servers
• Deploy web application firewall (WAF) rules to detect and block SSRF payloads in URL parameters
• Review access logs for requests to cloud metadata services or internal hostnames

Monitoring Recommendations

• Enable verbose logging on the URL ingest functionality to capture all submitted URLs
• Set up alerts for outbound connections from the OpenSift server to internal network segments
• Monitor DNS queries from the application server for internal hostname resolution attempts
• Implement egress filtering and log all outbound HTTP/HTTPS connections from the application

How to Mitigate CVE-2026-28677

Immediate Actions Required

• Upgrade OpenSift to version 1.6.3-alpha or later immediately
• Review application logs for evidence of exploitation attempts
• Implement network segmentation to limit the impact of potential SSRF attacks
• Block outbound connections from the application server to internal networks where not required

Patch Information

The vulnerability has been addressed in OpenSift version 1.6.3-alpha. The patch adds comprehensive URL validation including checks for embedded credentials and non-standard ports. Review the GitHub Security Advisory GHSA-5jfc-p787-2mf9 and the v1.6.3-alpha release for complete details. The fix was implemented in Pull Request #67.

Workarounds

• Deploy the application in localhost-only mode if external URL ingest is not required
• Implement a reverse proxy or WAF in front of OpenSift to filter and validate inbound URL parameters
• Apply network-level egress filtering to prevent the application from reaching internal resources
• Use cloud provider SSRF protections such as IMDSv2 on AWS to protect metadata endpoints

# Example: Restrict outbound connections using iptables (Linux)
# Block access to internal networks from the OpenSift application server
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP
iptables -A OUTPUT -d 169.254.169.254 -j DROP