protobuf.js: Denial of service from crafted field names in generated code

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

• CVE-2026-44294: 0.43% estimated exploitation activity in the next 30 days; percentile 37.42 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Impact An attacker who can provide or influence a protobuf schema or JSON descriptor may be able to make affected message types unusable by causing protobufjs runtime code generation to throw a syntax error. This is a denial of service issue for applications that load untrusted schemas or descriptors. Applications that only use trusted, application-defined schemas are not directly affected by this issue. The issue is not known to allow code execution by itself. Preconditions - The application must allow an attacker to control or influence a protobuf schema or JSON descriptor. - The crafted input must define a field name…

Published by the source

12 May 2026, 15:06 UTC

Last modified by the source

10 Sep 2026, 03:51 UTC

Source last checked

26 Oct 2026, 12:52 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2pr8-phx7-x9h3

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-2pr8-phx7-x9h3

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# Patch Next advisory brief: CVE-2026-44294

Advisory: protobuf.js: Denial of service from crafted field names in generated code
IDs: CVE-2026-44294, GHSA-2pr8-phx7-x9h3
Record: https://patchnext.com/advisories/cve-2026-44294 (revision 2, source checked 26 Oct 2026, 12:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: protobufjs 8.0.2, 7.5.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm protobufjs: affected <= 7.5.5; >= 8.0.0, <= 8.0.1; fixed in 7.5.6, 8.0.2

## Suggested inspection (read-only)
- `npm ls protobufjs --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on protobufjs.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-2pr8-phx7-x9h3 (OSV record GHSA-2pr8-phx7-x9h3 lists affected ranges: npm protobufjs >=0 =8.0.0 <8.0.2 (fixed))
- Verified: https://github.com/advisories/GHSA-2pr8-phx7-x9h3 (GitHub-reviewed advisory GHSA-2pr8-phx7-x9h3 lists affected ranges: npm protobufjs >=0 =8.0.0 <=8.0.1)

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