CVE-2025-67779 — Facebook React 19.0.2

What is CVE-2025-67779?

It was found that the fix addressing CVE-2025-55184 in React Server Components was incomplete and does not prevent a denial of service attack in a specific case. React Server Components versions 19.0.2, 19.1.3 and 19.2.2 are affected, allowing unsafe deserialization of payloads from HTTP requests to Server Function endpoints. This can cause an infinite loop that hangs the server process and may prevent future HTTP requests from being served.

The record classifies CVE-2025-67779 under weakness classes CWE-502, CWE-400. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 85 affected-product entries are recorded, across 2 vendors, listed below. The identifier was first published 321 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (FIRST): 19.9% probability of exploitation in the next 30 days, higher than 97.3% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 7.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2025-12-12

Is CVE-2025-67779 being exploited?

It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.

Affected products and versions

Facebook: React 19.0.2, React 19.1.3, React 19.2.2
Vercel: Next.js, Next.js 15.6.0, Next.js 16.1.0

Showing 6 of 85 recorded product entries.

How to fix CVE-2025-67779

Vendor advisory: https://react.dev/blog/2025/12/11/denial-of-service-and-source-code-exposure-in-react-server-components. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2025-67779

1 tracked threat in the Threadlinqs corpus references CVE-2025-67779, either in the campaign’s CVE list or as an indicator on the campaign record.

React2Shell CVE-2025-55182 — Multiple Threat Actors Actively Exploiting React Server Components RCE (CVSS 10.0) — CRITICAL · 2026-02-13

Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.