Categories
CVE-2026-44292 medium CVSS 5.3

Vulnerability in protobufjs (CVE-2026-44292)

Summary

Vulnerability in protobufjs (CVE-2026-44292). Risk of unauthorized operations or information disclosure. Exploitable via __proto__. Mitigation: upgrade to 8.0.2 or later.

Original description

The description as published by the source.

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated message constructors copied enumerable properties from a provided properties object without filtering the proto key. If an application constructed a message from an attacker-controlled plain object, an own enumerable proto property could alter the prototype of that individual message instance. This vulnerability is fixed in 7.5.6 and 8.0.2.

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-44292 has been found in protobufjs.
Attackers can target a specific entry point like __proto__ over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade protobufjs to 8.0.2 or later.
If unsure, ask your IT team or search "protobufjs CVE-2026-44292" on the vendor's site.

CVE-2026-44292 (protobufjs) — CWE-1321 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: __proto__ / Object.prototype / instanceof
Patched: 8.0.2 — apply immediately
Workaround: Do not pass attacker-controlled plain objects directly to generated message constructors with affected versions.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-1321) exists in protobufjs. Attackers reach the vulnerable code path via __proto__ without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of protobufjs. Attack surface: __proto__ / Object.prototype / instanceof.

🔥 Severity

Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 8.0.2.

🛡️ Workaround

Workaround: Do not pass attacker-controlled plain objects directly to generated message constructors with affected versions.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'protobufjs' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    grep -r 'protobufjs' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で protobufjs を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply temporary workaround mitigate
    Do not pass attacker-controlled plain objects directly to generated message constructors with affected versions.

    パッチが適用されるまでの応急処置として、Do not pass attacker-controlled plain objects directly to generated message constructors with affected versions. を実施。回避策の副作用 (機能低下) を確認した上で。

  3. 3
    Apply patch patch
    Upgrade protobufjs to 8.0.2

    ステージング環境で 8.0.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。

  4. 4
    Post-deployment verification verify
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

npm protobufjs
[{"type":"SEMVER","events":[{"introduced":"8.0.0"},{"fixed":"8.0.2"}]}]

References

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