pgparse is distributed as a Go module; fixes are released against the latest v0.x (and the latest v1.x once published). Please use the most recent release.

Please report security issues privately, not via public issues or pull requests:

• Preferred: open a GitHub Security Advisory.
• Alternatively, email the maintainer at the address on the GitHub profile.

Include a description, affected version, and ideally a minimal reproducer. You can expect an acknowledgement within a few days and a fix or mitigation plan for confirmed issues.

pgparse parses SQL text into an AST. It is designed to be safe to run on untrusted input:

• Parse never panics — internal panics are recovered and returned as errors.
• A depth limit bounds the AST that Parse builds, rejecting pathologically nested or chained input (deeply nested parentheses, but also long left-associative chains such as a+a+…+a, t JOIN t JOIN …, or SELECT…UNION…UNION…, which build depth without recursing while parsing). This protects two stacks: the parser's own, and — just as important — any recursive consumer of the result. Deparse, Walk, and a caller's own tree walk can all traverse any tree Parse returns without overflowing the stack. A stack overflow is a fatal runtime error that recover cannot catch, so this is enforced before the tree is returned.
• MaxInputBytes bounds input size, and MaxNodes bounds the number of AST atoms built from one input, to prevent unbounded memory allocation (including memory-amplifying input that packs many nodes into few bytes).
• It holds no shared mutable state and is safe for concurrent use.

Not in scope: pgparse is not a security control. It parses a pragmatic subset of PostgreSQL and is not the authoritative parser, and its read/write classification (Mutates/Classify) is purely syntactic — it cannot see side effects inside functions (e.g. SELECT nextval('s')). Do not use pgparse as the sole authority for SQL firewalling, read-only gating, or access control; enforce those with server-side controls (roles, default_transaction_read_only, read-replica connections).