CVE-2026-64877 Overview
CVE-2026-64877 is a SQL injection vulnerability in a ticketing REST API exposed by a Tenable appliance. An authenticated non-admin user can inject SQL statements through the API to read sensitive data stored in the appliance database. The flaw is tracked under CWE-20: Improper Input Validation and is described in Tenable Security Advisory TNS-2026-19.
The vulnerability requires only low-privilege authenticated access over the network. Successful exploitation compromises confidentiality, integrity, and availability of the appliance and downstream systems that rely on it.
Critical Impact
A low-privileged authenticated attacker can extract or modify sensitive appliance database contents through the ticketing REST API, resulting in full compromise of stored data.
Affected Products
- Tenable appliance exposing the ticketing REST API (see vendor advisory TNS-2026-19)
- Specific version details: refer to the Tenable Security Advisory TNS-2026-19
Discovery Timeline
- 2026-07-21 - CVE-2026-64877 published to NVD
- 2026-07-22 - Last updated in NVD database
Technical Details for CVE-2026-64877
Vulnerability Analysis
The vulnerability resides in the ticketing REST API of the affected appliance. User-supplied input reaches a SQL query without proper validation or parameterization. An authenticated non-admin user can submit crafted API parameters that alter query structure and read arbitrary data from the backing database.
Because the endpoint requires only a low-privilege session, any user account with API access becomes a viable attack primitive. The advisory indicates access to sensitive data stored in the appliance database, which typically includes ticket contents, user records, and configuration secrets.
The CWE-20 classification signals that input reaching the SQL layer is not filtered or sanitized to the expected structure. Combined with network reachability of the API, the flaw becomes usable from any position that can reach the appliance and hold valid credentials.
Root Cause
The root cause is improper input validation on parameters accepted by the ticketing REST API. The application concatenates or interpolates attacker-controlled values into SQL statements instead of using parameterized queries or strict allow-list validation.
Attack Vector
Exploitation follows a standard authenticated SQL injection pattern. The attacker authenticates to the appliance with any valid non-admin account, identifies a vulnerable ticketing API parameter, and submits payloads that alter query logic. Techniques include boolean-based inference, error-based extraction, UNION SELECT retrieval, and time-based blind extraction depending on the endpoint response behavior. Refer to the Tenable Security Advisory TNS-2026-19 for vendor-provided technical detail.
Detection Methods for CVE-2026-64877
Indicators of Compromise
- Ticketing REST API requests from non-admin accounts containing SQL metacharacters such as single quotes, UNION, SELECT, SLEEP(, or comment sequences (--, /*).
- Elevated response times or HTTP 500 errors on ticketing API endpoints correlated with unusual query strings or JSON bodies.
- Non-admin sessions issuing high-volume iterative API requests consistent with automated data extraction.
Detection Strategies
- Enable and centralize appliance access logs, then alert on ticketing API parameters containing SQL syntax tokens.
- Baseline normal ticketing API usage per user role and flag deviations in payload size, request cadence, or response entropy.
- Deploy a web application firewall or API gateway signature set that inspects requests to the ticketing endpoints for SQL injection patterns.
Monitoring Recommendations
- Forward appliance API and database audit logs to a central SIEM and retain them for retrospective hunting.
- Monitor database processes on the appliance for queries originating from the ticketing service that reference tables outside the ticketing schema.
- Track authentication events for non-admin accounts that begin issuing API traffic they did not previously generate.
How to Mitigate CVE-2026-64877
Immediate Actions Required
- Apply the vendor patch referenced in Tenable Security Advisory TNS-2026-19 as the primary remediation.
- Restrict network access to the appliance management and API interfaces to trusted administrative networks only.
- Audit non-admin accounts on the appliance and disable or rotate credentials for accounts that are unused or shared.
- Review appliance database and API logs for signs of prior exploitation before and after patching.
Patch Information
Tenable has published fixed versions and remediation guidance in TNS-2026-19. Administrators should upgrade to the version listed as fixed in the advisory. No public exploit is currently listed, and the CVE is not on the CISA Known Exploited Vulnerabilities catalog at the time of writing.
Workarounds
- Limit ticketing REST API access to specific administrative IP ranges using network access control lists until patching completes.
- Reduce the number of non-admin accounts with API access and enforce least privilege on remaining accounts.
- Enable API request logging and rate limiting on the appliance to slow automated injection attempts.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
