CVE-2025-55183VulnerabilityPublished 11 Dec 2025Updated 7 Jan 2026

CVE-2025-55183: Meta react-server-dom-webpack · Deserialization of Untrusted Data. Exposure of Sensitive System Information to an Unauthorized Actor

Affects Meta react-server-dom-webpackSource CVE Database V5

Not known to be exploited · 64% EPSS · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 64.2% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
npmreact-server-dom-parcel`pkg:npm/react-server-dom-parcel`Other threats	Affected =19.0.0 =19.1.0 =19.2.0	Fixed in–
npmreact-server-dom-turbopack`pkg:npm/react-server-dom-turbopack`Other threats	Affected =19.0.0 =19.1.0 =19.2.0	Fixed in–
npmreact-server-dom-webpack`pkg:npm/react-server-dom-webpack`Other threats	Affected =19.0.0 =19.1.0 =19.2.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Audit all Server Functions in affected React Server Components versions to identify any that expose stringified arguments or deserialize untrusted data. 2. Implement strict input validation and sanitization to prevent unsafe deserialization. 3. Limit the exposure of Server Functions to trusted internal networks or authenticated users where possible. 4. Monitor HTTP request patterns for unusual or suspicious payloads targeting Server Functions. 5. Stay updated with Meta's security advisories and apply patches or updates as soon as they become available. 6. Consider upgrading to later versions of React Server Components that address this vulnerability once released. 7. Employ Web Application Firewalls (WAFs) with custom rules to detect and block malformed requests targeting Server Functions. 8. Conduct regular code reviews focusing on serialization and deserialization logic to prevent similar issues. 9. Educate development teams about secure coding practices related to serialization and server-side data handling.

Description

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.

Impact

For European organizations, the primary impact is the potential exposure of proprietary server-side source code and sensitive implementation details. This can facilitate further attacks such as targeted exploitation, intellectual property theft, or bypassing security controls. Organizations relying on React Server Components for critical web applications may face increased risk of reconnaissance by threat actors. While the vulnerability does not directly compromise data integrity or availability, the confidentiality breach can undermine trust and compliance with data protection regulations like GDPR if sensitive information is indirectly exposed. The ease of remote exploitation without authentication increases the attack surface, especially for public-facing applications. This could lead to reputational damage and increased costs for incident response and remediation. The lack of known exploits in the wild suggests limited current exploitation but also highlights the need for proactive mitigation before attackers develop weaponized exploits.

CWE-502Deserialization of Untrusted Data (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #15OWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Architecture and Design · Implementation
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.
Implementation
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.
Implementation
Explicitly define a final object() to prevent deserialization.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
XML Security (opens in a new tab)
XML External Entity Prevention (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.2 (opens in a new tab)
V5.5.3 (opens in a new tab)
V5.5.1 (opens in a new tab)
Attack patterns
Object Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jan 2026, 19:42 UTC

WeaknessesCWE-502

Technical details

References

Community reviews

Related threats