The EPSS score of 0.00279 for CVE-2026-59893 badly misrepresents the actual risk. This is an algorithmic complexity vulnerability in sqlparse's dollar-quoting handling where the quadratic CPU consumption creates an asymmetric threat—doubling input size quadruples processing time, meaning an attacker spends very little to consume victim CPU at scale. This is not a low-probability exploitation; it's a deterministically effective DoS vector once an attacker knows the trigger.
The trigger itself is significant: dollar-quoting ($tag$ ... $tag$) is a legitimate PostgreSQL feature that most defensive pipelines don't target. An attacker using this syntax instead of standard string delimiters will likely evade WAFs and preprocessing filters that sanitize SQL before passing it to sqlparse. The obscurity of this vector is not accidental—it's a consequence of how few developers have mental models of the lexer's delimiter scanning implementation.
The deeper problem is the trust boundary around sqlparse. This library lives inside ORM tools, migration frameworks, query analyzers, and CI pipeline utilities as a transitive dependency that few teams know they carry. A developer using SQLAlchemy in a migration tool has sqlparse in their stack without ever choosing it. When user-controlled content flows through these pipelines, it hits the quadratic code path without anyone auditing that surface.
You should verify whether sqlparse appears in your dependency tree transitively—check your ORM's dependencies, your migration tooling, and any SQL formatting utilities. Instrument any sqlparse.parse(), format(), or split() calls processing untrusted input to detect anomalous CPU consumption. Be skeptical of the 0.6.0 patch: history shows that algorithmic complexity fixes in parsing libraries are often narrow, eliminating the documented trigger without fixing the underlying per-position scanning in the lexer. Assume the quadratic path may still exist through other input patterns, and plan monitoring accordingly.