CVE-2026-5038: 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 wh

Q: How do I fix CVE-2026-5038?

multer: upgrade to 2.2.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-5038 being exploited?

CVE-2026-5038 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-5038 affect?

CVE-2026-5038 affects multer. Severity is medium (CVSS 5.3). 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

Q: How urgent is CVE-2026-5038?

Priority 31/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-5038 is a medium-severity flaw (CVSS 5.3) affecting multer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 u

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-459
Published	2026-06-15
Last modified	2026-06-17

Publisher (CNA): openjs · Vendor: expressjs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-15 16:16 UTCPublished CVE record published
2026-06-17 10:58 UTCUpdated Record last modified

expressjs multer UPGRADE

Affected: >= 2.0.0 and < 2.2.0 · 3.0.0 alpha1

Fixed in: 2.2.0

Safe to downgrade to: a release before 2.0.0

1. Check installed version

npm ls multer

2. UPGRADE to 2.2.0

npm install multer@">=2.2.0"

3. If no update is available yet, DOWNGRADE to a release before 2.0.0

npm view multer versions npm install multer@"<2.0.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-5038?

multer: upgrade to 2.2.0. Exact commands for each OS are on this page.

Is CVE-2026-5038 being exploited?

CVE-2026-5038 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-5038 affect?

CVE-2026-5038 affects multer. Severity is medium (CVSS 5.3). 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

How urgent is CVE-2026-5038?

Priority 31/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-5079 HIGH 7.5 UPGRADE Impact: multer versions 1.0.0 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service via deeply

References

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