Medium exploit reference

CVE-2025-55183 — An information leak vulnerability exists in specific configurations of React Server…

An information leak vulnerability exists in specific configurations of React Server Components versions 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1, including the following packages: react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack. A specifically crafted HTTP request sent to a vulnerable Server Function may unsafely return the source code of any Server Function. Exploitation requires the existence of a Server Function which explicitly or implicitly exposes a stringified argument.

Published Dec 11, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Meta

Moderate

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 64.2% (30-day exploitation probability)+15
Technical severity (medium)+3
CISA SSVC: exploitation "poc"+5
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

64.23%

ahead of 99% of scored CVEs · Oct 14, 2026

Affects

Facebook

React and 4 more

CVSS base

5.3

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Facebook React, Meta React-server-dom-parcel, Meta React-server-dom-turbopack…).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Facebook	React	≥ 19.1.0 and < 19.1.3≥ 19.2.0 and < 19.2.2≥ 19.0.0 and < 19.0.2	Vulnerable	NIST National Vulnerability Database
Meta	React-server-dom-parcel	≥ 19.2.0 and ≤ 19.2.1≥ 19.1.0 and ≤ 19.1.2≥ 19.0.0 and ≤ 19.0.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Meta	React-server-dom-turbopack	≥ 19.2.0 and ≤ 19.2.1≥ 19.1.0 and ≤ 19.1.2≥ 19.0.0 and ≤ 19.0.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Meta	React-server-dom-webpack	≥ 19.2.0 and ≤ 19.2.1≥ 19.1.0 and ≤ 19.1.2≥ 19.0.0 and ≤ 19.0.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Vercel	Next.js	version 15.6.0-canary57version 15.6.0-canary53version 15.6.0-canary58version 15.6.0-canary59version 15.6.0-canary6version 15.6.0-canary7version 15.6.0-canary8version 15.6.0-canary9 and 80 more version 16.1.0version 16.1.0-canary0version 16.1.0-canary1version 15.6.0-canary56version 15.6.0-canary55version 15.6.0-canary54version 16.1.0-canary13version 15.6.0-canary52version 15.6.0-canary51version 15.6.0-canary50version 15.6.0-canary5version 15.6.0-canary49version 15.6.0-canary48version 16.1.0-canary3≥ 15.0.0 and < 15.0.7≥ 15.1.0 and < 15.1.11≥ 15.2.0 and < 15.2.8version 16.1.0-canary9version 16.1.0-canary8version 16.1.0-canary7version 16.1.0-canary6version 16.1.0-canary5version 16.1.0-canary4version 16.1.0-canary10version 16.1.0-canary2version 16.1.0-canary18version 16.1.0-canary17version 16.1.0-canary16version 16.1.0-canary15version 16.1.0-canary14version 15.6.0-canary47version 16.1.0-canary12version 16.1.0-canary11version 15.6.0-canary15version 15.6.0-canary25version 15.6.0-canary24version 15.6.0-canary23version 15.6.0-canary22version 15.6.0-canary21version 15.6.0-canary20version 15.6.0-canary2version 15.6.0-canary19version 15.6.0-canary18version 15.6.0-canary17version 15.6.0-canary16version 15.6.0-canary26version 15.6.0-canary14version 15.6.0-canary13version 15.6.0-canary12version 15.6.0-canary11version 15.6.0-canary10version 15.6.0-canary1version 15.6.0-canary0version 15.6.0≥ 16.0.0 and < 16.0.10≥ 15.5.0 and < 15.5.9≥ 15.4.0 and < 15.4.10version 15.6.0-canary36version 15.6.0-canary46version 15.6.0-canary45version 15.6.0-canary44version 15.6.0-canary43version 15.6.0-canary42version 15.6.0-canary41version 15.6.0-canary40version 15.6.0-canary4version 15.6.0-canary39version 15.6.0-canary38version 15.6.0-canary37≥ 15.3.0 and < 15.3.8version 15.6.0-canary35version 15.6.0-canary34version 15.6.0-canary33version 15.6.0-canary32version 15.6.0-canary31version 15.6.0-canary30version 15.6.0-canary3version 15.6.0-canary29version 15.6.0-canary28version 15.6.0-canary27	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.3	CVSS 3.1	Medium	3.9	1.4	cve-assign@fb.com via NIST National Vulnerability Database
5.3	CVSS 3.1	Medium	—	—	Meta via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N (score shown at the top: cve-assign@fb.com)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 64.23%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · meta/react-server-dom-webpack, meta/react-server-dom-turbopack, meta/react-server-dom-parcel
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 5.3
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Dec 11, 2025 · Meta

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

www.facebook.com/security/advisories/cve-2025-55183
Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
react.dev/blog/2025/12/11/denial-of-service-and-source-code-exposure-in-react-s
Exploit, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Facebook
every CVE for this vendor

Related CVEs (same products)

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Medium CVE-2026-94486 Next.js is a React framework for building full-stack web applications. From 16.0.0 until… 13d
Medium CVE-2026-94483 Next.js: Server-Side Request Forgery in Image Optimization 13d
Medium CVE-2026-94485 Next.js is a React framework for building full-stack web applications. From 16.0.0 until… 13d
Medium CVE-2026-94484 Next.js is a React framework for building full-stack web applications. From 15.0.0 until… 13d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-55183 is "An information leak vulnerability exists in specific configurations of React Server…", rated Medium. It affects React (Facebook); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 64.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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