Cyber Resilience

CVE-2026-34077

HighDDoS

Published: 02 June 2026

Published
02 June 2026
Modified
04 June 2026
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0026 17.0th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-34077 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Shopify React-Router. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 17.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

React Router is a router for React. In versions 7.7.0 through 7.13.1, when using React Router's unstable React Server Components (RSC) APIs, there is a potential client-side Cross-Site Scripting (XSS) vulnerability in the RSC redirect handling if redirects come from…

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untrusted sources. This does not impact applications that are not using the unstable RSC APIs in React Router. This is patched in version 7.13.2.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-42211Same product: Shopify React-Router
CVE-2026-33245Same product: Shopify React-Router
CVE-2026-21884Same product: Shopify React-Router
CVE-2026-42342Same product: Shopify React-Router
CVE-2025-59057Same product: Shopify React-Router
CVE-2026-22029Same product: Shopify React-Router
CVE-2026-3260Shared CWE-770
CVE-2025-27219Shared CWE-770
CVE-2026-20103Shared CWE-770
CVE-2026-29772Shared CWE-770

Affected Assets

shopify
react-router
7.0.0 — 7.14.0
turbo-stream
turbo stream
≤ 3.0.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-770

This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.

addresses: CWE-770

Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.

addresses: CWE-770

Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.

addresses: CWE-770

Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.

addresses: CWE-770

Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.

addresses: CWE-770

Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.

addresses: CWE-770

Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.

addresses: CWE-770

Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.

References