8.1

CVE-2026-42211: React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE

Analyzed
AliasesCGA-fj7j-p542-xv5wCGA-r8xm-p2pr-p53gGHSA-49rj-9fvp-4h2h
Published 02-06-2026Last modified 03-06-2026

Vulnerability summary

CVE-2026-42211 is a high (CVSS 8.1) Deserialization of Untrusted Data vulnerability in remix-run react-router. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35.9% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.42%
0%100%
Low · -0.21 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 3
RHSA-2026:29770SUSE-SU-2026:4585-1SUSE-SU-2026:4606-1CGA-CVXH-V32M-4C25

Timeline

  1. 02-06-2026
    PublishedVulnerability first disclosed.
  2. 03-06-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

36%

Versus all other CVEs

30-day change

Decrease -0.21 pp

From 0.62% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard3 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • vitess-24< 24.0.1-r2
Npm1 product
  • react-router≥ 7.0.0, < 7.14.2
Remix-run1 product
Shopify1 product
Wolfi1 product
  • vitess-24< 24.0.1-r2

5 vendors · 7 products

References

4 links