CVE-2026-55685: React Router is a router for React

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HIGH 7.5REMOTEUPGRADE

CVE-2026-55685 is a high-severity flaw (CVSS 7.5) affecting react-router. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-400, CWE-407
Published	2026-07-27
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: shopify

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-27 22:17 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

shopify react-router UPGRADE

Affected: >= 7.0.0 and < 7.18.0

Fixed in: 7.18.0

Safe to downgrade to: a release before 7.0.0

1. Check installed version

npm ls react-router

2. UPGRADE to 7.18.0

npm install react-router@">=7.18.0"

3. If no update is available yet, DOWNGRADE to a release before 7.0.0

npm view react-router versions npm install react-router@"<7.0.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

npm · react-router · FIXED · 7.18.0 · vulnerable: >= 7.0.0, < 7.18.0 · source

npm install react-router@">=7.18.0" npm ls react-router

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

RHEL 10 · grafana · NOT AFFECTED

RHEL 10 · ipa · DEFERRED

RHEL 8 · dotnet5.0-build-reference-packages · NOT AFFECTED

RHEL 8 · pcs · NOT AFFECTED

RHEL 9 · ipa · DEFERRED

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55685?

react-router: upgrade to 7.18.0. Exact commands for each OS are on this page.

Is CVE-2026-55685 being exploited?

CVE-2026-55685 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55685 affect?

CVE-2026-55685 affects react-router. Severity is high (CVSS 7.5). React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow

How urgent is CVE-2026-55685?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

Software pages

React vulnerabilities

Related CVEs

CVE-2026-53667 MEDIUM 6.9 UPGRADE React Router is a router for React
CVE-2026-53668 MEDIUM 6.9 UPGRADE React Router is a router for React
CVE-2026-53666 MEDIUM 6.1 UPGRADE React Router is a router for React
CVE-2026-53669 MEDIUM 6.1 UPGRADE React Router is a router for React

References

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