Vulnerability Report

CVE-2026-44288

Title: protobufjs: Overlong UTF-8 sequence bypass

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-44288.

CWE Category CWE-176

Published Date May 13, 2026

Modified Date May 19, 2026

Exploit Status Not Found

Score 5.3 CVSS v3.1

Exploit Probability (EPSS)

0.30%

Vulnerability Summary

CVE-2026-44288: protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs includes a minimal UTF-8 decoder that accepted overlong UTF-8 byte sequences and decoded them to their canonical characters instead of replacing them. An attacker who can provide protobuf binary data decoded through the affected UTF-8 path may be able to bypass application-level checks that inspect raw bytes before protobuf string decoding. For example, bytes that do not contain certain ASCII characters could decode to strings containing those characters. This vulnerability is fixed in 7.5.6 and 8.0.2.

Impacted Vendors

protobufjs_project 1

Reference Links

https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-q6x5-8v7m-xcrf

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

5.3

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-44288 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

May 19, 2026 MODIFIED

Vulnerability data updated via NVD.

May 13, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity LOW

Privileges N/A

Interaction NONE

CVSS Vector String


                                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected Stack

No specific products linked.