Is CVE-2026-45740 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-45740 being exploited in the wild.

How severe is CVE-2026-45740?

Medium severity, with a CVSS score of 5.3, published 13 May 2026.

Which products and versions are affected?

protobufjs (npm) SEMVER:introduced=0,fixed=7.5.8.

Is there a fix for CVE-2026-45740?

Yes. protobufjs (npm): upgrade to 7.5.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-45740 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-45740?

Check whether you run protobufjs (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-45740: protobufjs uncontrolled recursion in JSON descriptor expansion

CVE-2026-45740 · Severity: medium · CVSS 5.3 · Published 2026-05-13

A vulnerability in the protobufjs library, which is used to handle data serialization, can allow an attacker to crash an application. By providing a specially crafted data schema with excessive nesting, an attacker can cause the software to stop responding or shut down unexpectedly. This impacts the availability of services that process untrusted data schemas.

Technologies: protobufjs (npm). Vendors: npm.

Quick answers

Is CVE-2026-45740 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-45740 being exploited in the wild.
How severe is CVE-2026-45740?: Medium severity, with a CVSS score of 5.3, published 13 May 2026.
Which products and versions are affected?: protobufjs (npm) SEMVER:introduced=0,fixed=7.5.8.
Is there a fix for CVE-2026-45740?: Yes. protobufjs (npm): upgrade to 7.5.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45740 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-45740?: Check whether you run protobufjs (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

protobufjs (npm): upgrade to 7.5.8 or later
```
npm install protobufjs@7.5.8
```

Technical details

The protobufjs library fails to implement a depth limit during the expansion of nested JSON descriptors within the Root.fromJSON() and Namespace.addJSON() methods. An attacker can exploit this by providing a crafted JSON descriptor containing deeply nested 'nested' namespace objects. This leads to a stack overflow (CWE-674) as the JavaScript call stack is exhausted during recursive processing. The vulnerability can be triggered remotely if the application loads descriptors from untrusted sources. Patches are available in versions 7.5.8 and 8.2.0.

Affected products

protobufjs protobufjs <= 7.5.7, >= 8.0.0 < 8.2.0

Identifiers

CVE-2026-45740
GHSA-jggg-4jg4-v7c6

Timeline

2026-05-13: disclosed: NVD publication date
2026-05-19: advisory: GitHub Advisory published

References

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