Vulnerability report

Active exploitation observed Confirmed confidence In CISA KEV

CVE-2025-55182

react-server-dom-webpack Remote Code Execution

Meta / react-server-dom-webpack · 19.0.0 to <= 19.0.0

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Severity
CVSS 10.0 · Critical
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
99.8%
First observed
09 Jun 2026
Last observed
11 Sep 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2025-55182 is an unauthenticated vulnerability affecting Meta react-server-dom-webpack and 2 other products. A pre-authentication remote code execution vulnerability exists in React Server Components versions...

Is it exploited?

Yes. Previdian sensors observed exploitation attempts with confirmed confidence. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Meta / react-server-dom-webpack 19.0.0 to <= 19.0.0.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

react-server-dom-webpack Remote Code Execution

A pre-authentication remote code execution vulnerability exists in React Server Components versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0 including the following packages: react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack.

The vulnerable code unsafely deserializes payloads from HTTP requests to Server Function endpoints.

Vendor Product Affected Status
Meta react-server-dom-webpack Through 19.0.0 Affected
Meta react-server-dom-webpack Through 19.1.1 Affected
Meta react-server-dom-webpack Through 19.2.0 Affected
Meta react-server-dom-turbopack Through 19.0.0 Affected
Meta react-server-dom-turbopack Through 19.1.1 Affected
Meta react-server-dom-turbopack Through 19.2.0 Affected
Meta react-server-dom-parcel Through 19.0.0 Affected
Meta react-server-dom-parcel Through 19.1.1 Affected
Meta react-server-dom-parcel Through 19.2.0 Affected
Published
03 Dec 2025
Exploitation Reported
01 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

cisa nuclei_scanner malware

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 01 Jun 2026

A trusted third party reported exploitation.

Active exploitation observed

Previdian sensor

First observed 15 Jun 2026

Previdian first observed exploitation attempts targeting this vulnerability in our honeypot sensors.

Used in malware

CVE

Recorded 02 Jun 2026

Malware families have been linked to exploitation of this CVE.

Proof of concept available

Nuclei Templates

Recorded 12 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
The Shadowserver First 2026-06-01 00:00 UTC
CVE 2026-06-01 10:45 UTC
CISA 2026-06-02 14:04 UTC
Previdian 2026-07-03 10:18 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Previdian sensors recorded exploitation attempts targeting this vulnerability. The cards and chart show volume, unique attackers, and daily activity.

29,036

Attempts observed

124

Unique attacker IPs

11

Attacker countries

AE · BE · BG · DE · ER · FR · GB · ID · NL · SE · US

36

Sensors observed

CVE-2025-55182 exploitation attempts over the last 91 days

Daily events observed by Previdian sensors

Updated 11 Sep 2026

5
0
18
0
12
0
0
0
0
1
2
2
4
1
28
26
40
35
4
19
197
28
9
11
8
53
72
13
117
23
18
35
115
158
12
11
13
9
56
5
32
27
20
40
67
14
4
204
114
36
4
2
12
12
48
80
18
49
0
168
36
0
23
0
60
240
60
688
1,096
4,673
3,213
1,195
1,742
2,706
569
89
722
918
1,994
690
2,468
64
197
36
16
497
14
18
2,679
2,361
8
13 Jun 2 Jul 21 Jul 9 Aug 11 Sep

First observed 09 Jun 2026 · Last observed 11 Sep 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

Request telemetry access

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
30
24
3

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-55182.yaml 01 Jun 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

99.8%

Weaknesses

Deserialization of Untrusted Data CWE-502

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

CVE-2025-55182: React2Shell Pre-Auth RCE

1dayexploit · Created 2026-09-07 14:30:00 UTC

React2Shell (CVE-2025-55182): Pre-auth RCE via insecure deserialization in React Server Components. CVSS 10.0 critical.

React Server Components - Remote Code Execution

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. Indicators of compromise added (266)

    Indicators of compromise recorded

  2. Observed by Previdian sensors

    Evidence-backed exploitation signal

  3. Public PoC available

    Public proof-of-concept code published

  4. First public exploitation report

    Exploit observed in malware

  5. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  6. Nuclei template available

    Scanner coverage available

  7. KEV confirmed by CVE

    Exploitation attested by an external source

  8. Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  9. CVE published

    Vulnerability disclosed publicly

  10. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2025-55182

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2025-55182",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.99802,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 29036, "sensors": 36 }
}