Bump multer from 2.3.0 to 2.4.0

[dependabot]

Bumps multer from 2.3.0 to 2.4.0.

Release notes

Sourced from multer's releases.

v2.4.0

Highlights

multer finally supports Google Cloud Functions and Firebase 🎉

These platforms read the request body before your code runs, so multer's classic req.pipe(busboy) received nothing: empty req.body, empty req.files, and nearly a decade of duplicated issues.

The new streamHandler option closes that gap: you decide how the body reaches the parser, so the pre-read rawBody just works (see image).

const multer = require('multer')
const upload = multer({
storage: multer.memoryStorage(),
streamHandler: (req, busboy) => {
// Cloud Functions / Firebase expose the pre-read body here
if (req.rawBody) busboy.end(req.rawBody)
else req.pipe(busboy)
}
})
app.post('/upload', upload.single('file'), (req, res) => {
res.json({ name: req.file.originalname, size: req.file.size })
})

This landed thanks to community PRs going back to 2017; their authors are credited as co-authors in the release.

Important: Security

• Fix CVE-2026-88932 (GHSA-3pph-fpjx-jg34)

What's Changed

• docs: remove README translations by @​UlisesGascon in expressjs/multer#1463
• ci: add macOS to the test matrix by @​kilisamemarisaaa in expressjs/multer#1464
• feat. improve wording for LIMIT_UNEXPECTED_FILE error code by @​flashbag in expressjs/multer#426
• feat: add filename to file errors by @​UjjwalKumar239 in expressjs/multer#1416
• refactor: remove concat-stream dependency by @​Phillip9587 in expressjs/multer#1356
• fix: reject non-integer fileSize limits by @​abhu85 in expressjs/multer#1395
• fix: allow exactly limits.parts parts by @​deepakganesh78 in expressjs/multer#1446
• fix: do not consume maxCount for files skipped by fileFilter by @​Sagargupta16 in expressjs/multer#1426
• fix: validate all limits at construction time by @​ShubhamOulkar in expressjs/multer#1335
• test: cover storage engine _removeFile invocation semantics by @​kilisamemarisaaa in expressjs/multer#1460
• feat: accept a function for limits by @​hossein-zare in expressjs/multer#1133
• fix: add flush option to disk storage to fsync files before completion by @​kilisamemarisaaa in expressjs/multer#1458
• feat: expose busboy defCharset, highWaterMark and fileHwm options by @​UlisesGascon in expressjs/multer#1465
• docs: describe the file stream contract for storage engines by @​UlisesGascon in expressjs/multer#1468

... (truncated)

Changelog

Sourced from multer's changelog.

2.4.0

• Fix CVE-2026-88932 (GHSA-3pph-fpjx-jg34)
• Add filename to LIMIT_FILE_SIZE and LIMIT_UNEXPECTED_FILE errors (#1416)
• Accept a function for limits, called with the request, to set limits per request (#1133)
• Add opt-in flush option to DiskStorage to fsync files before the callback runs (#1458)
• Expose busboy's defCharset, highWaterMark and fileHwm options (#1465)
• Add streamHandler option to feed busboy from pre-consumed bodies (Google Cloud Functions, Firebase) (#1466)
• Allow multer.diskStorage() to be called without options (#1471)
• Decode WHATWG-escaped characters (%0A, %0D, %22) in field names, matching file.originalname since 2.3.0: req.body keys, file.fieldname and err.field now carry the real name. If you matched the escaped spelling as a workaround, use the real name now (#1473)
• Report the decoded filename in err.filename on LIMIT_FILE_SIZE errors, matching file.originalname (#1478)
• Reject non-integer or negative limits values at construction time; a float limit silently disabled the check (#1395, #1335)
• Accept requests with exactly limits.parts parts; LIMIT_PART_COUNT now fires only when the limit is exceeded. If you set parts one higher to work around this, you can drop the extra one (#1446)
• Files skipped by fileFilter no longer count towards maxCount (#1426)
• Change the LIMIT_UNEXPECTED_FILE message to "Unexpected file field" (#426)
• Remove the concat-stream dependency (#1356)
• Docs: add JSDoc to the public API and document the storage engine stream contract (#1467, #1468)
• Docs: add FormData upload examples (#896)
• Docs: remove the translated READMEs (#1463)
• Internal: run the test suite on macOS (#1464)

Commits

• 35979e5 2.4.0 (#1469)
• b888532 chore(deps): bump github/codeql-action/upload-sarif to 4.37.9 (#1474)
• e6bcd7d chore(deps): bump github/codeql-action/analyze from 4.37.4 to 4.37.9 (#1475)
• 00dec43 chore(deps): bump github/codeql-action/init from 4.37.4 to 4.37.9 (#1476)
• 8d5c3b7 feat: allow diskStorage without options (#1471)
• 02f6e82 fix: report the decoded filename on LIMIT_FILE_SIZE (#1478)
• bc3f72d fix: decode escaped field names, not just filenames (#1473)
• 2661325 docs: add JSDoc to the public API (#1467)
• 53337f9 fix: remove late-completing uploads aborted before the engine names them
• 7f2c9ab feat: add streamHandler option to feed busboy from pre-consumed bodies (#1466)
• Additional commits viewable in compare view

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 46.19%. Comparing base (4621207) to head (7df5503).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2227      +/-   ##
==========================================
+ Coverage   42.45%   46.19%   +3.73%     
==========================================
  Files        1040     1040              
  Lines       17160    17160              
  Branches     3133     3133              
==========================================
+ Hits         7286     7927     +641     
+ Misses       9874     9233     -641     

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