CVE-2025-59845 — @apollo/sandbox
HIGHCVE-2025-59845 is a high-severity (CVSS 8.2) CWE-346 vulnerability in @apollo/sandbox. A fix is available for @apollo/sandbox — see the affected versions and patch details below.
Apollo Embedded Sandbox and Explorer vulnerable to CSRF via window.postMessage origin-validation bypass
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-59845.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@apollo/sandboxnpm@apollo/explorernpmDescription
Impact
A Cross-Site Request Forgery (CSRF) vulnerability was identified in Apollo’s Embedded Sandbox and Embedded Explorer.
The vulnerability arises from missing origin validation in the client-side code that handles window.postMessage events. A malicious website can send forged messages to the embedding page, causing the victim’s browser to execute arbitrary GraphQL queries or mutations against their GraphQL server while authenticated with the victim’s cookies.
Who is impacted
Anyone embedding Apollo Sandbox or Apollo Explorer in their website may have been affected by this vulnerability.
- Users who embed Apollo Sandbox or Apollo Explorer in their websites via npm packages (
@apollo/sandboxand@apollo/explorer) or direct links to Apollo’s CDN. - Users running Apollo Router with embedded Sandbox enabled. This served the vulnerable code from Apollo’s CDN.
- Users running Apollo Server with embedded Sandbox or Explorer enabled. Embedded Sandbox is enabled by default when
NODE_ENVis not set toproduction, and embedded Sandbox and Explorer can also be enabled in production mode via landing page plugins. This served the vulnerable code from Apollo’s CDN.
While all of the above methods of serving Embedded Sandbox and Explorer were vulnerable, Apollo has already updated its CDN to remove all vulnerable versions. Unless you install the npm package @apollo/sandbox or @apollo/explorer directly into your website’s front end code, no action is necessary: the vulnerability has already been mitigated.
Users who do not embed Sandbox/Explorer on their websites, or who only run Apollo Router/Server with production defaults were never impacted. The use of non-embedded Sandbox and Explorer hosted on studio.apollographql.com is not vulnerable.
Scope of impact
The vulnerability allows a malicious website to open the vulnerable website in a new window and force it to send GraphQL requests to its origin. The requests themselves are not "cross-origin" as they are directly issued from the vulnerable website, but their contents are dictated by the malicious website.
The malicious website cannot read the responses to the GraphQL operations, but the operations may be mutations with side effects (such as using credentials to update app-specific data access controls). These operations can contain the browser user's cookies, and the vulnerable website may be on a private network otherwise inaccessible to the attacker. Operations sent this way look and exactly like legitimate operations sent by a human interacting with the embedded Sandbox or Explorer.
Patches
The issue has been fixed by adding strict origin validation to DOM message handling.
@apollo/sandbox: Patched in v2.7.2 and later@apollo/explorer: Patched in v3.7.3 and later- Apollo’s CDN embeds have been updated to patched versions. This protects embeds based on
<script>tags pointing to Apollo’s CDN, as well as the Apollo Router and Apollo Server features. No action is necessary to adopt the fix in this case.
If you manually edited the <script> tag provided by the Explorer or Sandbox UI to replace the version string _latest, v2, or v3 with a specific git-style SHA, you may find that the Explorer or Sandbox UI does not currently load. To fix this, use a supported URL instead, as documented for Sandbox or Explorer. (The third-party Go GraphQL server gqlgen provides a function ApolloSandboxHandler which serves an unsupported URL and was broken by our mitigations; upgrading to gqlgen v0.17.81 will resolve this issue.)
Workarounds
- If you are using Apollo Server, ensure
NODE_ENV=productionis set in production to avoid unintentionally serving embedded Sandbox. - Customers not using embedded Sandbox/Explorer are not affected and do not need to take action.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @apollo/sandbox | all versions | 2.7.2npm install @apollo/sandbox@2.7.2 |
| 📦npm | @apollo/explorer | all versions | 3.7.3npm install @apollo/explorer@3.7.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @apollo/sandbox, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @apollo/sandbox to 2.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59845 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2025-59845 in your dependencies?
Find it across npm, including transitive dependencies.