CVE-2026-5038
multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required.
Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path.
Workarounds: None.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required.
Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path.
Workarounds: None.
- Record
CVE-2026-5038- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-459
- Updated
- 2026-11-02
EUVDEUVD-2026-36728
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required.
Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path.
Workarounds: None.
- Record
EUVD-2026-36728- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3p4h-7m6x-2hcm
Multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Impact
A vulnerability in Multer allows an attacker to trigger a Denial of Service (DoS) by aborting or sending malformed multipart uploads, causing orphaned partial files to accumulate on disk when using diskStorage.
Patches
Users should upgrade to 2.2.0, 3.0.0-alpha.2 or higher
Workarounds
None
- Record
GHSA-3p4h-7m6x-2hcm- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-459
- Updated
- 2026-11-02
NVD
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required.
Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path.
Workarounds: None.
- Record
CVE-2026-5038- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-459
- Updated
- 2026-11-02
OSV
multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Impact: multer versions 2.0.0-alpha.1 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service when using diskStorage. Aborted or malformed multipart uploads leave orphaned partial files on disk because the Readable.pipe() call does not propagate the stream destroy signal to the underlying fs.WriteStream. An attacker can exhaust disk space by triggering many aborted uploads, with no application bug required.
Patches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease). Both versions track in-flight write streams and clean them up on the abort path.
Workarounds: None.
- Record
CVE-2026-5038- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-459
- Updated
- 2026-11-02
OSVGHSA-3p4h-7m6x-2hcm
Multer vulnerable to Denial of Service via incomplete cleanup of aborted uploads
Impact
A vulnerability in Multer allows an attacker to trigger a Denial of Service (DoS) by aborting or sending malformed multipart uploads, causing orphaned partial files to accumulate on disk when using diskStorage.
Patches
Users should upgrade to 2.2.0, 3.0.0-alpha.2 or higher
Workarounds
None
- Record
GHSA-3p4h-7m6x-2hcm- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-459
- Updated
- 2026-11-02
OSVROOT-APP-NPM-CVE-2026-5038 No score
CVE-2026-5038 in multer - Patched by Root
Root has patched CVE-2026-5038 in the multer package for Root:npm. Multiple fixed versions available.
- Record
ROOT-APP-NPM-CVE-2026-5038- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
multernpm |
2.0.0-alpha.1 up to 2.2.0 | 2.2.0 |
multernpm |
3.0.0-alpha.1 up to 3.0.0-alpha.2 | 3.0.0-alpha.2 |
multerRoot:npm |
before 2.0.2-aikido.5 | 2.0.2-aikido.52.0.2-aikido.62.1.1-aikido.32.1.1-aikido.22.1.1-aikido.42.0.2-aikido.72.2.0-aikido.12.2.0-aikido.2 |
@rootio/multerRoot:npm |
before 2.0.2-root.io.5 | 2.0.2-root.io.52.0.2-root.io.62.1.1-root.io.32.1.1-root.io.22.1.1-root.io.42.0.2-root.io.72.2.0-root.io.12.2.0-root.io.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5038 is a medium vulnerability (CVSS 5.3) in Expressjs Multer, published June 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. Fixed in multer 2.2.0.