NVD / CVE Program· CNA GitHub_M

CVE-2026-42342: React Router vulnerable to DoS via unbounded path expansion in __manifest endpoint

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: @remix-run/server-runtime (npm) 2.17.5; react-router (npm) 7.15.0; golang-github-prometheus-prometheus (SUSE:Linux Enterprise Module for Package Hub 15 SP7) 3.13.2-150100.4.40.2.
Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to @remix-run/server-runtime (npm) 2.17.5; react-router (npm) 7.15.0; golang-github-prometheus-prometheus (SUSE:Linux Enterprise Module for Package Hub 15 SP7) 3.13.2-150100.4.40.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

React Router is a router for React. In versions 7.0.0 through 7.14.x of react-router and versions 2.10.0 through 2.17.4 of @remix-run/server-runtime, certain crafted requests can consume disproportionate server resources via unbounded path expansion in the __manifest endpoint, resulting in response time degradation and/or service unavailability for end users. This affects React Router Framework Mode applications as well as Remix applications. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in react-router version 7.15.0 and @remix-run/server-runtime version 2.17.5.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Jun 2, 2026
Updated: Jul 21, 2026
EPSS: 0.2% · 22th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.5; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
shopify	react-router	cpe:2.3:a:shopify:react-router
shopify	remix-run\/server-runtime	cpe:2.3:a:shopify:remix-run\/server-runtime

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

shopify react-router7.0.0 and later · before 7.15.0
shopify remix-run/server-runtime2.10.0 and later · before 2.17.5

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

remix-run @remix-run/server-runtime
- >= 2.10.0, < 2.17.5affected
remix-run react-router
- >= 7.0.0, < 7.15.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
npm	@remix-run/server-runtime	from 2.10.0 · before 2.17.5	2.17.5
npm	react-router	from 7.0.0 · before 7.15.0	7.15.0
SUSE:Linux Enterprise Module for Package Hub 15 SP7	golang-github-prometheus-prometheus	before 3.13.2-150100.4.40.2	3.13.2-150100.4.40.2

Same product

shopify: all records

Other highest-scoring records for the same primary product.

CVE-2026-55685React Router: Unauthenticated Denial of Service via Inefficient Route Matching
34Monitor
CVE-2026-42211React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE
32Monitor
CVE-2026-21884React Router SSR XSS in ScrollRestoration
32Monitor

Published before and after this one in the same product

← EarlierCVE-2026-34077Jun 2, 2026 · React Router vulnerable to Denial of Service via reflected user input in single-fetch
30Monitor
← EarlierCVE-2026-40181Jun 2, 2026 · React Router's same-origin redirect with path starting // causes open redirect via protocol-relative URL reinterpretation
26Monitor
Later →CVE-2026-53666Jul 27, 2026 · React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration
24Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
npm:@remix-run/server-runtime	2.17.5	Package registry (OSV)
npm:react-router	7.15.0	Package registry (OSV)
suse:golang-github-prometheus-prometheus	3.13.2-150100.4.40.2 · SUSE:Linux Enterprise Module for Package Hub 15 SP7	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-5568555 days apartReact Router: Unauthenticated Denial of Service via Inefficient Route Matching
34Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

ShopifyHackerOne · paid

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0653 · Jul 28, 2026(React Ürünleri Güvenlik Zafiyeti )
TR-26-0303 · Jun 4, 2026(React Router Güvenlik Zafiyeti )

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

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

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records