{"id":"PYSEC-2026-249","details":"Starlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form() accepts max_fields and max_part_size to bound resource consumption while parsing form data. These limits are enforced for multipart/form-data, but silently ignored for application/x-www-form-urlencoded. An unauthenticated attacker can therefore send a urlencoded body with an arbitrarily large number of fields or an arbitrarily large field, even when the application configured limits it believed would apply. This vulnerability is fixed in 1.3.1.","aliases":["CVE-2026-54283","GHSA-82w8-qh3p-5jfq"],"modified":"2026-06-27T11:15:06.800792374Z","published":"2026-06-22T18:16:46.943Z","references":[{"type":"ADVISORY","url":"https://github.com/Kludex/starlette/security/advisories/GHSA-82w8-qh3p-5jfq"}],"affected":[{"package":{"name":"starlette","ecosystem":"PyPI","purl":"pkg:pypi/starlette"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.4.1"},{"fixed":"1.3.1"}]}],"versions":["0.10.0","0.10.1","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.11.0","0.11.1","0.11.2","0.11.3","0.11.4","0.12.0","0.12.0b1","0.12.0b2","0.12.0b3","0.12.1","0.12.10","0.12.11","0.12.12","0.12.13","0.12.2","0.12.3","0.12.4","0.12.5","0.12.6","0.12.7","0.12.8","0.12.9","0.13.0","0.13.1","0.13.2","0.13.3","0.13.4","0.13.5","0.13.6","0.13.7","0.13.8","0.14.0","0.14.1","0.14.2","0.15.0","0.16.0","0.17.0","0.17.1","0.18.0","0.19.0","0.19.1","0.20.0","0.20.1","0.20.2","0.20.3","0.20.4","0.21.0","0.22.0","0.23.0","0.23.1","0.24.0","0.25.0","0.26.0","0.26.0.post1","0.26.1","0.27.0","0.28.0","0.29.0","0.30.0","0.31.0","0.31.1","0.32.0","0.32.0.post1","0.33.0","0.34.0","0.35.0","0.35.1","0.36.0","0.36.1","0.36.2","0.36.3","0.37.0","0.37.1","0.37.2","0.38.0","0.38.1","0.38.2","0.38.3","0.38.4","0.38.5","0.38.6","0.39.0","0.39.1","0.39.2","0.4.1","0.4.2","0.40.0","0.41.0","0.41.1","0.41.2","0.41.3","0.42.0","0.43.0","0.44.0","0.45.0","0.45.1","0.45.2","0.45.3","0.46.0","0.46.1","0.46.2","0.47.0","0.47.1","0.47.2","0.47.3","0.48.0","0.49.0","0.49.1","0.49.2","0.49.3","0.5.0","0.5.1","0.5.2","0.5.3","0.5.4","0.5.5","0.50.0","0.51.0","0.52.0","0.52.1","0.6.0","0.6.1","0.6.2","0.6.3","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.9.0","0.9.1","0.9.10","0.9.11","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6","0.9.7","0.9.8","0.9.9","1.0.0","1.0.0rc1","1.0.1","1.1.0","1.2.0","1.2.1","1.3.0"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/starlette/PYSEC-2026-249.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}