CVE-2026-15830: Potential denial-of-service vulnerability via nested geometry collections

An issue was discovered in Django 5.2 before 5.2.17 and 6.0 before 6.0.8. GeoDjango's django.contrib.gis.geos.GEOSGeometry is subject to a potential denial-of-service when parsing deeply nested GEOMETRYCOLLECTION objects supplied as well-known text (WKT), well-known binary (WKB), or hex-encoded WKB, which triggers unbounded recursion and a segmentation fault in the underlying GEOS library. Spatial field lookups and the django.contrib.gis.forms.GeometryField form field are also affected. Earlier, unsupported Django series (such as 5.1.x, 5.0.x, and 4.2.x) were not evaluated and may also be affected. Django would like to thank Andrew MacPherson and kimchunbok for reporting this issue.