What is CVE-2026-45740?

CVE-2026-45740 is a medium-severity vulnerability in Protobufjs Protobuf.js, classified under Uncontrolled Recursion. CVSS score: 5.3/10. Published 2026-05-13.

How severe is CVE-2026-45740?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Protobufjs Protobuf.js

CVE-2026-45740

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.8 and 8.2.0, protobufjs could recurse without a depth limit while expanding nested JSON descriptors through Root.fromJSON() and Namespace.addJSON(). A crafted JSON descriptor with deeply nested namespace definitions could cause the JavaScript call stack to be exhausted during descriptor loading. This vulnerability is fixed in 7.5.8 and 8.2.0.

Published 2026-05-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.005 (38.6th percentile), scored 2026-10-21.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Protobufjs Protobuf.js — versions < 7.5.8, >= 8.0.0, < 8.2.0
Protobufjs Project

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

github.com/protobufjs/protobuf.js/security/advisories/GHSA-jggg-4jg4-v7c6 (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-45740?: CVE-2026-45740 is a medium-severity vulnerability in Protobufjs Protobuf.js, classified under Uncontrolled Recursion. CVSS score: 5.3/10. Published 2026-05-13.
How severe is CVE-2026-45740?: Medium severity. CVSS v3 base score is 5.3 out of 10.