GHSA-w37m-7fhw-fmv9
Next Server Actions Source Code Exposure
Medium
npm
- Severity
- 5.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-1395 Dependency on Vulnerable Third-Party Component
- CWE-497 Exposure of Sensitive System Information to an Unauthorized Control Sphere
- CWE-502 Deserialization of Untrusted Data
- Fix
15.0.6- Upgrade next to this version or later
Description
A vulnerability affects certain React packages for versions 19.0.0, 19.0.1, 19.1.0, 19.1.1, 19.1.2, 19.2.0, and 19.2.1 and frameworks that use the affected packages, including Next.js 15.x and 16.x using the App Router. The issue is tracked upstream as CVE-2025-55183.
A malicious HTTP request can be crafted and sent to any App Router endpoint that can return the compiled source code of Server Functions. This could reveal business logic, but would not expose secrets unless they were hardcoded directly into Server Function code.
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| next | >= 15.0.0-canary.0, < 15.0.6 |
15.0.6 |
| next | >= 15.1.1-canary.0, < 15.1.10 |
15.1.10 |
| next | >= 15.2.0-canary.0, < 15.2.7 |
15.2.7 |
| next | >= 15.3.0-canary.0, < 15.3.7 |
15.3.7 |
| next | >= 15.4.0-canary.0, < 15.4.9 |
15.4.9 |
| next | >= 15.5.1-canary.0, < 15.5.8 |
15.5.8 |
| next | >= 15.6.0-canary.0, < 15.6.0-canary.59 |
15.6.0-canary.59 |
| next | >= 16.0.0-beta.0, < 16.0.9 |
16.0.9 |
| next | >= 16.1.0-canary.0, < 16.1.0-canary.17 |
16.1.0-canary.17 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
next npm → 15.0.6
- npm
npm install next@15.0.6- yarn
yarn add next@15.0.6- pnpm
pnpm add next@15.0.6
Severity breakdown
CVSS 3.1 5.3
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
Weakness
CWE-1395: Dependency on Vulnerable Third-Party Component
The product has a dependency on a third-party component that contains one or more known vulnerabilities.
How to prevent it
- Requirements, Policy: In some industries such as healthcare [REF-1320] [REF-1322] or technologies such as the cloud [REF-1321], it might be unclear about who is responsible for applying patches for third-party vulnerabilities: the vendor, the operator/customer, or a separate service. Clarifying roles and responsibilities can be important to minimize confusion or unnecessary delay when third-party vulnerabilities are disclosed.
- Requirements: Require a Bill of Materials for all components and sub-components of the product. For software, require a Software Bill of Materials (SBOM) [REF-1247] [REF-1311].
- Architecture and Design, Implementation, Integration, Manufacturing: Maintain a Bill of Materials for all components and sub-components of the product. For software, maintain a Software Bill of Materials (SBOM). According to [REF-1247], "An SBOM is a formal, machine-readable inventory of software components and dependencies, information about those components, and their hierarchical relationships."
- Operation, Patching and Maintenance: Actively monitor when a third-party component vendor announces vulnerability patches; fix the third-party component as soon as possible; and make it easy for operators/customers to obtain and apply the patch.
- Operation, Patching and Maintenance: Continuously monitor changes in each of the product's components, especially when the changes indicate new vulnerabilities, end-of-life (EOL) plans, etc.
CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere
The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.
How to prevent it
- Architecture and Design, Implementation: Production applications should never use methods that generate internal details such as stack traces and error messages unless that information is directly committed to a log that is not viewable by the end user. All error message text should be HTML entity encoded before being written to the log file to protect against potential cross-site scripting attacks against the viewer of the logs
CWE-502: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How to prevent it
- 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.
- Architecture and Design, Implementation: Make fields transient to protect them from deserialization. An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
- Implementation: Avoid having unnecessary types or gadgets (a sequence of instances and method invocations that can self-execute during the deserialization process, often found in libraries) available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.
- Architecture and Design, Implementation: Employ cryptography of the data or code for protection. However, it's important to note that it would still be client-side security. This is risky because if the client is compromised then the security implemented on the client (the cryptography) can be bypassed.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Packages
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-673q-mjm6-r5xr Next.js: Unauthenticated Remote Code Execution in `use cache` functions returning typed arrays | Critical | Also affects next |
| GHSA-2464-fhr4-w9xw Next.js: Unauthenticated Remote Code Execution in Image Optimization API when SVG files are used | Critical | Also affects next |
| GHSA-p3m5-59mp-jv5r Next.js: Denial of Service in App Router using Server Actions | High | Also affects next |
| GHSA-3w37-wq28-93x7 Next.js: Pending `use cache` fill can leak Draft Mode content into regular responses and persisted pages | Medium | Also affects next |
| GHSA-4jqv-mc3x-m676 Next.js has cache poisoning of SSG and ISR pages in self-hosted applications | Medium | Also affects next |
| GHSA-39w2-rjm5-chcv Next.js has information disclosure in development server's Model Context Protocol endpoint | Medium | Also affects next |
| GHSA-f87g-xv8r-7p7x Next.js has information disclosure in App Router metadata image routes via dynamicParams bypass | Medium | Also affects next |
| GHSA-mcj8-r9mp-w47p Next.js has cache poisoning in SSG/ISR rendering that leads to cross-user content substitution and persistent denial of service | Medium | Also affects next |
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