6.1

CVE-2026-53666: remix-run react-router Unsafe Reflection

CVSS: 6.1v3.1MediumAnalyzed
AliasesCGA-4242-p36w-q6h2CGA-ch6c-9vcc-g3v6CGA-j7ph-jc27-q76r
Published 27-07-2026Last modified 28-07-2026
Open JSON

Vulnerability summary

CVE-2026-53666 is a medium (CVSS 6.1) Unsafe Reflection vulnerability in remix-run react-router. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.11 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-V4XJ-XGV4-X468

Timeline

  1. 27-07-2026
    PublishedVulnerability first disclosed.
  2. 28-07-2026
    Last modifiedVulnerability information updated.

Description

React Router is a router for React. In versions 6.4.0 through 7.17.0, if application code was written in a way that allows attacker-supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for an attacker to trigger unexpected constructor execution on the client, which would in turn trigger an outbound network request. This is only possible with very specific (and unlikely) application-layer code. Note that this does not impact an application if it is using Declarative Mode. It only impacts Framework Mode and Data Mode applications that perform manual SSR/hydration. This issue has been fixed in version 7.18.0.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.11 pp

From 0.30% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard9 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • keycloak-26.5< 26.5.7-r3
  • keycloak-26.5-iamguarded-compat< 26.5.7-r3
  • keycloak-26.7< 26.7.2-r1
Wolfi4 products
  • keycloak-26.5< 26.5.7-r3
  • keycloak-26.5-iamguarded-compat< 26.5.7-r3
  • vitess-24< 24.0.2-r7
  • vitess-24-compat< 24.0.3-r7
Npm1 product
  • react-router≥ 6.4.0, < 7.18.0
Remix-run1 product
Shopify1 product

5 vendors · 16 products

References

8 links