apollo-server-core vulnerable to URL-based XSS attack affecting IE11 on default landing page

Exploitation

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

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact The default landing page contained HTML to display a sample curl command which is made visible if the full landing page bundle could not be fetched from Apollo's CDN. The server's URL is directly interpolated into this command inside the browser from window.location.href. On some older browsers such as IE11, this value is not URI-encoded. On such browsers, opening a malicious URL pointing at an Apollo Router could cause execution of attacker-controlled JavaScript. This only affects Apollo Server with the default landing page enabled. Old browsers visiting your server may be affected if ANY of these apply: - You do not pass any landing page plugin to the plugins option of new ApolloServer. - You pass ApolloServerPluginLandingPageLocalDefault() or ApolloServerPluginLandingPageProductionDefault() to the plugins option of new ApolloServer. Browsers visiting your server are NOT affected if ANY of these apply: - You pass ApolloServerPluginLandingPageDisabled() to the plugins option…

Published by the source

18 Aug 2022, 18:55 UTC

Last modified by the source

7 Jan 2023, 05:05 UTC

Source last checked

26 Oct 2026, 12:06 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2fvv-qxrq-7jq6

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-2fvv-qxrq-7jq6

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# Patch Next advisory brief: GHSA-2fvv-qxrq-7jq6

Advisory: apollo-server-core vulnerable to URL-based XSS attack affecting IE11 on default landing page
IDs: GHSA-2fvv-qxrq-7jq6
Record: https://patchnext.com/advisories/ghsa-2fvv-qxrq-7jq6 (revision 2, source checked 26 Oct 2026, 12:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apollo-server-core 3.10.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm apollo-server-core: affected >= 3.0.0, < 3.10.1; fixed in 3.10.1

## Suggested inspection (read-only)
- `npm ls apollo-server-core --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 apollo-server-core.
- 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-2fvv-qxrq-7jq6 (OSV record GHSA-2fvv-qxrq-7jq6 lists affected ranges: npm apollo-server-core >=3.0.0 <3.10.1 (fixed))
- Verified: https://github.com/advisories/GHSA-2fvv-qxrq-7jq6 (GitHub-reviewed advisory GHSA-2fvv-qxrq-7jq6 lists affected ranges: npm apollo-server-core >=3.0.0 <3.10.1)

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