CVE-2026-44294 protobufjs: Denial of service from crafted field names in generated code

Medium 5.3 Published 13 May 2026 Updated 13 May 2026

Attackers can cause denial of service in applications using protobufjs by providing crafted schemas with unescaped control characters in field names.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-44294?

CVE-2026-44294 is a medium-severity denial of service vulnerability in protobufjs protobuf.js, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated JavaScript property accessors from schema-controlled field and oneof names. Certain control characters in field names were not escaped before being embedded into generated function bodies. A crafted schema or JSON descriptor could therefore cause generated encode, decode, verify, or conversion functions to fail during compilation. This vulnerability is fixed in 7.5.6 and 8.0.2.

Weakness: CWE-20

Which versions are affected by CVE-2026-44294?

4 open source packages ship an affected version, including protobufjs. It affects 1 product.

Package	Affected	Fixed in
`protobufjs` npm	All versions	`7.5.6`
`protobufjs` npm	All versions	`7.5.6`
`protobufjs` npm	From `8.0.0`	`8.0.2`
`protobufjs` npm	From `8.0.0`	`8.0.2`

Products include Protobufjs Project Protobufjs.

How do I fix CVE-2026-44294?

Upgrade protobufjs to a fixed version for your release line: 7.5.6 or 8.0.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-44294 being exploited?

There is no known exploitation of CVE-2026-44294 in the wild and no public exploit code.

Sources

Also known as CLEANSTART-2026-QS69313, CLEANSTART-2026-TM62649, ECHO-dcd3-a6fa-dfa9, GHSA-2pr8-phx7-x9h3, MINI-3c7c-8xgv-pmgg, MINI-3cmf-cm7c-2846 and 15 more.