CVE-2026-44295Network attack vector

Code execution via unsanitized generated identifiers

Published May 13, 2026 · Updated May 13, 2026

Code injection in protobuf.js CLI before 1.2.1 and 2.0.0 through 2.0.1 allows attackers to embed code in generated JavaScript. The pbjs static generators write schema-controlled namespace, enum, service, and derived full names as JavaScript identifiers without sufficient sanitization. Exploitation requires attacker influence over a schema or JSON descriptor and subsequent execution or import of the generated file, where injected code runs in the application or build process.

CVSS severity8.7
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Code injection in protobuf.js CLI before 1.2.1 and 2.0.0 through 2.0.1 allows attackers to embed code in generated JavaScript. The pbjs static generators write schema-controlled namespace, enum, service, and derived full names as JavaScript identifiers without sufficient sanitization. Exploitation requires attacker influence over a schema or JSON descriptor and subsequent execution or import of the generated file, where injected code runs in the application or build process.

The record

CVE
CVE-2026-44295
Published
May 13, 2026
Updated
May 13, 2026
Vendor
protobufjs
Product
protobuf.js
Classifications
CWE-94, T1204.002
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 1.2.1
  2. Affected versionversion=>= 2.0.0, < 2.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

protobufjs · protobuf.jsversion=< 1.2.1; version=>= 2.0.0, < 2.0.2

Published CVSS scores

8.7GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo