Meta React Server Components Remote Code Execution
CVE-2025-55182 is a critical-severity deserialization of untrusted data vulnerability in react-server-dom-webpack from Meta, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected react-server-dom-webpack versions: 19.0.0 and earlier; 19.1.0 through 19.1.1; 19.2.0 and earlier. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on December 5, 2025, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Next.js to 15.0.5 or 15.1.9 or 15.2.6 or 15.3.6, whichever matches your release line, or a later version.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Read the advisory on react.dev for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Meta | react-server-dom-webpack | 19.0.0 and earlier; 19.1.0 through 19.1.1; 19.2.0 and earlier | Not stated |
| Meta | react-server-dom-turbopack | 19.0.0 and earlier; 19.1.0 through 19.1.1; 19.2.0 and earlier | Not stated |
| Meta | react-server-dom-parcel | 19.0.0 and earlier; 19.1.0 through 19.1.1; 19.2.0 and earlier | Not stated |
| React | 19.0.0; 19.1.0; 19.1.1; 19.2.0 | Not stated | |
| Vercel | Next.js | 15.0.0 up to, but not including, 15.0.5; 15.1.0 up to, but not including, 15.1.9; 15.2.0 up to, but not including, 15.2.6; 15.3.0 up to, but not including, 15.3.6; 15.4.0 up to, but not including, 15.4.8; 15.5.0 up to, but not including, 15.5.7; 16.0.0 up to, but not including, 16.0.7; 14.3.0; and 2 more ranges | 15.0.5, 15.1.9, 15.2.6, 15.3.6, 15.4.8, 15.5.7 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (fb.com).
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- openwall.com/lists/oss-security/2025/12/03/4Mailing List, Third Party Advisory
Third-party and government advisories
Other references
- news.ycombinator.com/item?id=46136026Issue Tracking
Other vulnerabilities in react-server-dom-webpack
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
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