CVE-2026-42211: React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE
Noroxi assessment
Priority: Monitor (action score 32/100)
- 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: 0.41% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: remix-run react-router 7.14.2.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to remix-run react-router 7.14.2 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 7.14.1, when using Framework Mode, a combination of steps could potentially allow unauthorized remote code execution (RCE) through external requests. This attack requires the application code to have an existing prototype pollution vulnerability, which can then be leveraged in a 2-step attack where the second step triggers unauthorized RCE on the remote server. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.14.2.
- Published
- Jun 2, 2026
- Updated
- Jul 21, 2026
- EPSS
- 0.4% · 36th percentile
- CWE
- CWE-502
Report tools
Action score
32
Low priority for now.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 8.1
- 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.
Is your version affected? Check itNoroxi 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.
We use this product, ask for helpAffected 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 |
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 react-router
- >= 7.0.0, < 7.14.2affected
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 7.14.2
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | react-router | from 7.0.0 · before 7.14.2 | 7.14.2 |
| Red Hat:hummingbird:1 | opentelemetry-collector-contrib | before 0:0.155.0-0.1.hum1 | 0:0.155.0-0.1.hum1 |
| 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 recordsOther highest-scoring records for the same primary product.
- CVE-2026-55685React Router: Unauthenticated Denial of Service via Inefficient Route Matching34Monitor
- CVE-2026-21884React Router SSR XSS in ScrollRestoration32Monitor
- CVE-2026-42342React Router vulnerable to DoS via unbounded path expansion in __manifest endpoint30Monitor
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-fetch30Monitor
- ← EarlierCVE-2026-40181Jun 2, 2026 · React Router's same-origin redirect with path starting // causes open redirect via protocol-relative URL reinterpretation26Monitor
- Later →CVE-2026-53666Jul 27, 2026 · React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration24Monitor
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 |
|---|---|---|
| remix-run react-router | 7.14.2 · description | Vendor (CNA) |
| npm:react-router | 7.14.2 | Package registry (OSV) |
| red hat:opentelemetry-collector-contrib | 0:0.155.0-0.1.hum1 · Red Hat:hummingbird:1 | 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.
Bug bounty scope
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-26-0303 · Jun 4, 2026(React Router Güvenlik Zafiyeti )
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate.
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.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-502 · Deserialization of Untrusted DataCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Root cause
Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.
The bug in code
The whole CWE-502 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
payload = sock.recv(65536)
job = pickle.loads(payload)Fixed
payload = sock.recv(65536)
if not hmac.compare_digest(sign(payload), header_sig):
raise PermissionError("invalid signature")
job = JobSchema.validate(json.loads(payload))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
—
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.