CVE-2026-11927 Overview
CVE-2026-11927 affects IBM Security Verify Identity Access. The reverse proxy component may allow attackers to inject parameters into requests forwarded to third-party services. The flaw is classified under [CWE-74] Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection).
The vulnerability arises when the reverse proxy fails to properly sanitize input before forwarding requests. Attackers can manipulate downstream service behavior by injecting unauthorized parameters. This class of injection may lead to unauthorized data access, request tampering, or downstream logic manipulation depending on the target service.
Critical Impact
Parameter injection through the reverse proxy can alter requests sent to trusted third-party services, potentially bypassing access controls or manipulating downstream logic.
Affected Products
- IBM Security Verify Identity Access (reverse proxy component)
Discovery Timeline
- 2026-09-15 - CVE-2026-11927 published to NVD
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-11927
Vulnerability Analysis
IBM Security Verify Identity Access provides access management and reverse proxy functionality for enterprise identity workflows. The reverse proxy relays authenticated requests to backend and third-party services. This vulnerability allows an attacker to inject additional parameters into those outbound requests.
The classification [CWE-74] indicates the product does not neutralize special elements when constructing requests for downstream components. As a result, attacker-supplied data can be interpreted as protocol-level parameters by the receiving service. The impact depends on how each downstream service processes the injected parameters.
Root Cause
The root cause is improper neutralization of input used to build outbound HTTP requests. The reverse proxy propagates client-controlled values without adequate encoding or validation. When these values contain reserved characters or parameter delimiters, the downstream service parses them as additional parameters rather than opaque data.
Attack Vector
An attacker with the ability to send requests through the reverse proxy can craft input containing parameter delimiters. The proxy forwards these values to third-party services, which then interpret them as legitimate request parameters. This can override intended values, add unauthorized parameters, or alter the downstream request semantics. Refer to the IBM Support Page for vendor-specific technical details.
Detection Methods for CVE-2026-11927
Indicators of Compromise
- Reverse proxy access logs containing unexpected reserved characters such as &, ?, or = inside client-supplied fields.
- Outbound requests to third-party services with duplicated parameter names or unexpected parameter values.
- Third-party service audit logs showing requests attributed to Verify Identity Access with anomalous parameter sets.
Detection Strategies
- Inspect proxied HTTP requests for parameter smuggling patterns where client input contains encoded delimiters that decode into new parameters.
- Correlate identity access reverse proxy logs with third-party service logs to identify parameter mismatches between issued and received requests.
- Baseline expected parameter sets per downstream integration and alert on deviations.
Monitoring Recommendations
- Forward reverse proxy and downstream service logs to a centralized analytics platform for cross-correlation.
- Monitor for repeated failed downstream requests that could indicate probing for injection points.
- Track configuration changes to junction and third-party integration definitions within Verify Identity Access.
How to Mitigate CVE-2026-11927
Immediate Actions Required
- Review the IBM Support Page and apply the fix version identified by IBM for Security Verify Identity Access.
- Audit reverse proxy junction definitions and third-party integrations for exposed endpoints that accept user-controlled parameters.
- Restrict which downstream services the reverse proxy can reach until patching is complete.
Patch Information
IBM has published remediation guidance on the IBM Support Page. Administrators should apply the fixed version of IBM Security Verify Identity Access as specified in the advisory. Verify the running build after upgrade and validate reverse proxy behavior against known-good test cases.
Workarounds
- Implement strict allow-lists on parameters that the reverse proxy forwards to third-party services.
- Encode or reject reserved URL characters in client-supplied input before it reaches the proxy layer.
- Terminate and rebuild outbound requests at an intermediary gateway that enforces parameter normalization.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
