CVE-2026-54271Network attack vector

Code injection via unsafe descriptor-derived references

Published Jun 22, 2026 · Updated Jun 22, 2026

Code injection in protobufjs-cli before 1.3.2 and 2.0.0 through 2.4.2 allows attackers to emit attacker-controlled JavaScript. The pbjs static and static-module generators emit unsafe JavaScript references from crafted names in pre-parsed JSON descriptors. Exploitation requires an attacker-influenced descriptor, later execution or import of the generated file, and invocation of an affected API path; .proto parsing is unaffected.

CVSS severity8.2
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in protobufjs-cli before 1.3.2 and 2.0.0 through 2.4.2 allows attackers to emit attacker-controlled JavaScript. The pbjs static and static-module generators emit unsafe JavaScript references from crafted names in pre-parsed JSON descriptors. Exploitation requires an attacker-influenced descriptor, later execution or import of the generated file, and invocation of an affected API path; .proto parsing is unaffected.

The record

CVE
CVE-2026-54271
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
protobufjs
Product
protobufjs-cli
Classifications
CWE-94, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 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=< 1.3.2
  2. Affected versionversion=>= 2.0.0, < 2.4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

protobufjs · protobufjs-cliversion=< 1.3.2; version=>= 2.0.0, < 2.4.2

Published CVSS scores

8.2GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1203Exploitation for Client Execution

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

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Your stack

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