# CVE-2026-44288

## Summary

- **CVE ID:** CVE-2026-44288
- **Severity:** MEDIUM
- **CVSS Score:** 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **CWE:** CWE-176
- **Published:** May 13, 2026
- **Last Modified:** May 13, 2026

## Description

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.

## Affected Products

- protobufjs — protobuf.js (< 7.5.6)
- protobufjs — protobuf.js (>= 8.0.0, < 8.0.2)

## References

- [CNA](https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-q6x5-8v7m-xcrf)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 22.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._