GHSA-MH25-X5HQ-WRQP league/commonmark: Denial of service via colliding heading slugs

Impact UniqueSlugNormalizer::normalize makes each slug document-unique by searching for an unused numeric suffix, but restarts that search from 1 on every collision. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σk−1 = OK². An attacker...

league/commonmark: Denial of service via colliding heading slugs

Impact UniqueSlugNormalizer::normalize makes each slug document-unique by searching for an unused numeric suffix, but restarts that search from 1 on every collision. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σk−1 = OK². An attacker...