RCE in Protobufjs Protobuf.js
CVE-2026-44291
protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs used plain objects with inherited prototypes for internal type lookup tables used by generated encode and decode functions. If Object.prototype had already been polluted, those lookup tables could resolve attacker-controlled inherited properties as valid protobuf type information. This could cause attacker-controlled strings to be emitted into generated JavaScript code. This vulnerability is fixed in 7.5.6 and 8.0.2.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (35.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.001
Affected products
- Protobufjs Protobuf.js — versions < 7.5.6, >= 8.0.0, < 8.0.2
- Protobufjs Project
Weakness classification (CWE)
References
- github.com/protobufjs/protobuf.js/security/advisories/GHSA-75px-5xx7-5xc7 (Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-44291?
- CVE-2026-44291 is a high-severity vulnerability in Protobufjs Protobuf.js, classified under Code Injection. CVSS score: 8.1/10. Published 2026-05-13.
- How severe is CVE-2026-44291?
- High severity. CVSS v3 base score is 8.1 out of 10.