CVE-2026-42542

In TDengine prior to version 3.4.1.15, a Data Reader user with admin_user role on a TDengine Cloud DB instance could execute create udf, even though standard users should have read-only permissions for non-database objects and commands like show dnodes and create user were denied.

In TDengine before version 3.4.1.14, the tGetToken() function in the SQL parser mishandles string literals ending with a backslash, causing an out-of-bounds read. An authenticated user can submit a crafted SQL query to crash the server and potentially leak adjacent memory.

In TDengine before version 3.4.1.15, the transDecompressMsg() function reads the STransCompMsg.contLen field without first validating that the RPC packet contains the 8-byte STransCompMsg structure, leading to an unauthenticated out-of-bounds read, uncontrolled allocation, integer underflow, and server crash.

In TDengine prior to version 3.4.1.15, a user with create UDF privilege can upload a crafted shared library and install it as a user-defined function, then execute arbitrary C code on the server side through database queries.

In TDengine version 3.4.1.6 and earlier, the trimString() function in parUtil.c incorrectly checks string length before processing SQL escape sequences, leading to a one-byte out-of-bounds write to the stack buffer tmpTokenBuf. This can cause denial of service and potentially remote code execution.

In TDengine Enterprise before version 3.4.1.15, an authenticated low-privilege SQL user could run KILL SSMIGRATE <id> against an active shared-storage migration because the MND_OPER_SSMIGRATE_DB privilege check was commented out in mndProcessKillSsMigrateReq.