fix: enforce mimeTypes restriction when useTempFiles is enabled#16255
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PatrikKozak merged 8 commits intopayloadcms:mainfrom Apr 14, 2026
Merged
fix: enforce mimeTypes restriction when useTempFiles is enabled#16255PatrikKozak merged 8 commits intopayloadcms:mainfrom
PatrikKozak merged 8 commits intopayloadcms:mainfrom
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When `useTempFiles` is true, `file.data` is an empty buffer so `fileTypeFromBuffer` returns undefined. The fallback extension-based validation was gated behind `!useTempFiles`, which meant it was skipped entirely — allowing any file type to bypass MIME restrictions. Remove the `!useTempFiles` condition so extension-based validation always runs when buffer detection fails, regardless of temp file mode. Fixes payloadcms#16233 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Hey @PatrikKozak — just a heads up, the first commit (a2b31a2) has a |
paulpopus
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🚀 This is included in version v3.83.0 |
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…oadcms#16255) This replaces payloadcms#16236 which was auto-closed when the fork was deleted. # Overview Fixes MIME type validation being skipped on upload collections when `upload.useTempFiles: true` is set globally. ## Key Changes - Use `fileTypeFromFile` for temp files instead of loading the full buffer — avoids reading large files (e.g. 2GB video) into memory just for MIME detection - Removed the `!useTempFiles` gate that was causing the entire fallback validation block to be skipped - Added `tempFilePath` to the `File` type directly instead of intersecting it at the call site - Full file content is loaded lazily via `getFileBuffer()` and only when needed for SVG/PDF content validation ## Design Decisions The original code used the `useTempFiles` config flag to decide whether to run fallback validation, but checking `tempFilePath` directly is more accurate, files uploaded via the local API always have `file.data` populated even when `useTempFiles` is enabled. Simply removing the gate (as originally suggested) would've fixed the extension check but left `validateSvg` broken, since it would still run on an empty buffer and always return safe. Fixes payloadcms#16233. --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> Co-authored-by: Patrik Kozak <35232443+PatrikKozak@users.noreply.github.com> Co-authored-by: Paul Popus <paul@payloadcms.com>
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This replaces #16236 which was auto-closed when the fork was deleted.
Overview
Fixes MIME type validation being skipped on upload collections when
upload.useTempFiles: trueis set globally.Key Changes
fileTypeFromFilefor temp files instead of loading the full buffer — avoids reading large files (e.g. 2GB video) into memory just for MIME detection!useTempFilesgate that was causing the entire fallback validation block to be skippedtempFilePathto theFiletype directly instead of intersecting it at the call sitegetFileBuffer()and only when needed for SVG/PDF content validationDesign Decisions
The original code used the
useTempFilesconfig flag to decide whether to run fallback validation, but checkingtempFilePathdirectly is more accurate, files uploaded via the local API always havefile.datapopulated even whenuseTempFilesis enabled.Simply removing the gate (as originally suggested) would've fixed the extension check but left
validateSvgbroken, since it would still run on an empty buffer and always return safe.Fixes #16233.