CVE-2026-84305: sqlparse: Reindentation of tuple lists causes near-cap quadratic CPU consumption

September 1, 2026

When SQL is formatted with reindentation enabled, ReindentFilter repeatedly rebuilds prefixes of the current statement to calculate token offsets. An attacker who controls SQL sent to this opt-in formatting path can supply a parenthesized tuple list that remains just below the grouping-token cap. Thousands of offset calculations then traverse an expanding token tree, causing multi-second CPU consumption from an input of roughly 16 KB and degrading service availability.

References

github.com/advisories/GHSA-cfqr-cjx5-5jcm
github.com/andialbrecht/sqlparse/commit/a51df6d9e2d31b44be9adb6bc8732517db6bf96b
github.com/andialbrecht/sqlparse/releases/tag/0.6.0
github.com/andialbrecht/sqlparse/security/advisories/GHSA-cfqr-cjx5-5jcm
nvd.nist.gov/vuln/detail/CVE-2026-84305

Code Behaviors & Features

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