CVE-2026-77078Network attack vectorHinoki check available

Process crash via crafted multipart field names

Published Aug 28, 2026 · Updated Aug 28, 2026

Uncaught exception in Multer before 2.3.0 allows remote attackers to crash the Node.js process via crafted multipart field names. Multer passes the first field's huge numeric index to append-field, creating a maximum-length sparse array, then the second field triggers an uncaught RangeError when append-field pushes beyond that length. Any unauthenticated client that can reach an application route parsing multipart forms can terminate that Node.js process, interrupting service until it restarts.

CVSS severity7.5
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncaught exception in Multer before 2.3.0 allows remote attackers to crash the Node.js process via crafted multipart field names. Multer passes the first field's huge numeric index to append-field, creating a maximum-length sparse array, then the second field triggers an uncaught RangeError when append-field pushes beyond that length. Any unauthenticated client that can reach an application route parsing multipart forms can terminate that Node.js process, interrupting service until it restarts.

The record

CVE
CVE-2026-77078
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
body-parser
Product
Multer
Classifications
CWE-248, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

body-parser · Multerversion=0 <2.3.0

Published CVSS scores

7.5Express.jsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-248Uncaught Exception
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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