CVE-2026-88402 Overview
CVE-2026-88402 is a SQL injection vulnerability in the checkSQL function of NocoBase v2.1.21. NocoBase is an open-source no-code and low-code development platform used to build business applications and internal tools. The flaw allows unauthenticated attackers to inject crafted SQL statements through inputs processed by checkSQL, exposing sensitive database contents.
The vulnerability is classified under [CWE-89] Improper Neutralization of Special Elements used in an SQL Command. It is network-exploitable, requires no privileges, and needs no user interaction. Successful exploitation compromises confidentiality, integrity, and availability of the underlying database.
Critical Impact
Remote, unauthenticated attackers can read, modify, or destroy database contents through crafted SQL payloads passed to the checkSQL function.
Affected Products
- NocoBase v2.1.21
- Deployments exposing the checkSQL code path to untrusted input
- Downstream applications built on the affected NocoBase release
Discovery Timeline
- 2026-09-21 - CVE-2026-88402 published to the National Vulnerability Database
- 2026-09-22 - Last updated in NVD database
Technical Details for CVE-2026-88402
Vulnerability Analysis
The vulnerability lives in the checkSQL function within NocoBase v2.1.21. The function accepts SQL-related input and forwards it to the database layer without adequate neutralization of SQL metacharacters. Attackers supply crafted payloads that break out of the intended query context and append or modify SQL statements.
Because the endpoint reachable through checkSQL does not require authentication or elevated privileges, exploitation collapses to sending a single crafted HTTP request. The attacker can enumerate schemas, extract records, or issue write operations depending on the privileges granted to the database account NocoBase uses.
Root Cause
The root cause is missing parameterization and input sanitization within checkSQL. User-controlled data is concatenated into a SQL query string rather than bound as a parameter. This pattern maps directly to [CWE-89] and defeats any downstream input filtering because the injected fragment becomes part of the parsed query.
Attack Vector
Exploitation occurs over the network against the exposed NocoBase HTTP interface. An attacker submits a request that reaches checkSQL with a payload containing SQL syntax, such as boolean-based or UNION-based injection primitives. The response, timing behavior, or database error output allows extraction of arbitrary rows from tables accessible to the NocoBase database user.
For technical discussion and reproduction notes, see the GitHub Issue Discussion.
Detection Methods for CVE-2026-88402
Indicators of Compromise
- HTTP requests targeting NocoBase endpoints that invoke checkSQL and contain SQL metacharacters such as ', --, UNION, or SLEEP(.
- Database logs showing malformed queries, syntax errors, or unexpected UNION SELECT statements originating from the NocoBase service account.
- Sudden spikes in database read volume or long-running queries tied to the NocoBase application user.
- Outbound connections from the NocoBase host to attacker-controlled infrastructure following anomalous query activity.
Detection Strategies
- Deploy web application firewall signatures that flag SQL injection patterns against NocoBase HTTP routes.
- Correlate application access logs with database query logs to identify requests that map to unexpected SQL statements.
- Alert on database errors emitted by the NocoBase user, since normal application flow should produce well-formed queries.
Monitoring Recommendations
- Enable verbose query logging on the NocoBase database backend during triage windows.
- Monitor for authentication-less requests reaching administrative or diagnostic NocoBase endpoints.
- Baseline normal query patterns for the NocoBase service account and alert on deviations such as information_schema access.
How to Mitigate CVE-2026-88402
Immediate Actions Required
- Restrict network access to NocoBase v2.1.21 instances until an upstream fix is applied, allowing only trusted clients through a reverse proxy or VPN.
- Rotate database credentials used by NocoBase and enforce least-privilege permissions on that account.
- Audit database logs for evidence of injection attempts referencing the checkSQL code path.
Patch Information
No vendor advisory or patched release is listed in the NVD entry at the time of publication. Monitor the NocoBase repository and the GitHub Issue Discussion for a fixed version and upgrade guidance.
Workarounds
- Place NocoBase behind a web application firewall configured to block SQL injection payloads targeting endpoints that reach checkSQL.
- Remove or disable network exposure of any diagnostic routes that surface the checkSQL function to unauthenticated users.
- Constrain the database role used by NocoBase to read-only access on non-essential schemas to limit blast radius.
- Enable database-side query filtering or a proxy such as ProxySQL to reject statements containing suspicious patterns from the NocoBase user.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.