Improper Handling of Unicode Encoding in protobuf.js - CVE-2026-44288
Published: May 12, 2026
Vulnerability identifier: #VU131166
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-44288
CWE-ID: CWE-176
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: protobuf.js
Affected software:
protobuf.js
protobuf.js
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass application-level integrity checks.
The vulnerability exists due to improper handling of unicode encoding in the minimal UTF-8 decoder when decoding attacker-influenced protobuf binary data through the affected UTF-8 path. A remote attacker can provide specially crafted protobuf binary data to bypass application-level integrity checks.
The issue is exposed only when the affected protobuf string field is decoded through protobufjs's minimal UTF-8 decoder rather than a native UTF-8 decoder, and the application relies on byte-level filtering before protobuf string decoding in a security-sensitive context.
How to mitigate CVE-2026-44288
Install security update from vendor's website.