Vulnerability-Lookup

GHSA-P297-FM68-3Q8C

Vulnerability from github – Published: 2026-09-10 20:19 – Updated: 2026-09-10 20:19

Summary

Angular: Information Leak via `HttpTransferCache` Bypass When Using `withRequestsMadeViaParent`

Details

A security bypass vulnerability was discovered in @angular/common when Server-Side Rendering (SSR) and hydration are enabled in applications using a hierarchical HttpClient configuration with withRequestsMadeViaParent().

The HttpTransferCache utility optimizes hydration by caching outgoing HTTP requests performed during SSR and transferring the cached state to the client-side application via TransferState (serialized as JSON in <script id="ng-state">). Following the remediation of CVE-2026-50170, HttpTransferCache automatically skips caching requests that contain authentication headers or credentials (Authorization, Cookie, withCredentials, etc.).

However, when a child HttpClient delegates to a parent client via withRequestsMadeViaParent(), the child's TransferCache interceptor evaluates whether the request is eligible for caching before delegating to the parent client's interceptor chain.

If an outgoing request originates as anonymous from the child client, the child TransferCache marks the request as cacheable. When the request reaches a parent interceptor that injects sensitive authentication credentials (such as an Authorization header or API token), the parent TransferCache correctly skips caching the authenticated request. However, when the backend returns the private, authenticated response, the child TransferCache still stores the response in TransferState based on its initial pre-delegation evaluation.

Impact

Successful exploitation allows sensitive, user-specific information belonging to an authenticated user to be leaked to unauthenticated or unauthorized users. This occurs when:

During SSR, a child HttpClient initiates an unauthenticated request that is subsequently authenticated by a parent interceptor.
The authenticated response body is cached into the SSR-rendered HTML page (TransferState).
The rendered HTML page is stored by a shared caching layer (e.g., CDN, edge cache, or reverse proxy) or served across user sessions.
Subsequent visitors requesting the same page receive the cached HTML containing the previous user's private data.

Attack Preconditions & Vulnerable Configurations

An application is affected only if all of the following conditions are met:

SSR and Hydration Enabled: The application uses Server-Side Rendering with hydration enabled (e.g., via provideClientHydration()).
Hierarchical HttpClient with Delegation: The application configures a child HttpClient using withRequestsMadeViaParent().
Parent-Level Authentication Injection: Authentication credentials (such as Authorization headers, session cookies, or custom API tokens filtered via withHttpTransferCacheOptions) are attached by an interceptor in the parent injector chain rather than on the initial child request.
Shared HTML Caching: The SSR HTML responses are cached by a shared caching layer (CDN, reverse proxy, or application-level HTML cache).

Vulnerable Code Pattern Example

// Parent Injector / Application Config
export const appConfig: ApplicationConfig = {
  providers: [
    provideHttpClient(
      // Parent interceptor attaches sensitive Authorization header
      withInterceptors([
        (req, next) => next(req.clone({ setHeaders: { Authorization: `Bearer ${getToken()}` } }))
      ])
    ),
  ],
};

// Child Injector / Feature or Component Config
const childClient = createEnvironmentInjector(
  [
    // Child delegates to parent; TransferCache evaluates req BEFORE parent auth interceptor runs
    provideHttpClient(withRequestsMadeViaParent()),
  ],
  parentInjector
).get(HttpClient);

// Request originates without auth headers -> marked cacheable by child TransferCache
childClient.get('/api/user/profile').subscribe();

Patches

The issue is resolved by updating @angular/common to run root interceptors in the terminal request chain so that delegated clients leave inherited root interceptors to the parent chain, preventing duplicate execution and ensuring HttpTransferCache evaluates cache eligibility after parent request interceptors run.

22.1.1
21.2.20
20.3.28

Workarounds & Mitigations

For applications that cannot immediately upgrade to a patched version, use one of the following mitigations:

Attach Credentials Before or Within the Child Client: Ensure authentication headers (e.g., Authorization) are attached directly when constructing the request or via an interceptor configured directly on the child HttpClient, rather than relying solely on parent interceptors.
Apply Explicit Cache Filters on the Child Client: Configure withHttpTransferCacheOptions with a filter on the child client that explicitly excludes endpoints returning user-specific or sensitive data: ts provideClientHydration( withHttpTransferCacheOptions({ filter: (req) => !req.url.includes('/api/private/'), }) )
Disable HTTP Transfer Cache for Sensitive Routes: If specific SSR routes handle user-authenticated data, disable transfer caching for those requests or ensure the SSR response sets Cache-Control: no-store / private headers at your edge/CDN layer so personalized HTML is never shared.

Severity

4.0 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "22.0.0"
            },
            {
              "fixed": "22.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "21.0.0"
            },
            {
              "fixed": "21.2.20"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "20.0.0"
            },
            {
              "fixed": "20.3.28"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "19.2.25"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-88059"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-524"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-10T20:19:19Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "A security bypass vulnerability was discovered in `@angular/common` when Server-Side Rendering (SSR) and hydration are enabled in applications using a hierarchical `HttpClient` configuration with `withRequestsMadeViaParent()`.\n\nThe `HttpTransferCache` utility optimizes hydration by caching outgoing HTTP requests performed during SSR and transferring the cached state to the client-side application via `TransferState` (serialized as JSON in `\u003cscript id=\"ng-state\"\u003e`). Following the remediation of [CVE-2026-50170](https://github.com/angular/angular/security/advisories/GHSA-q6f4-qqrg-jv6x), `HttpTransferCache` automatically skips caching requests that contain authentication headers or credentials (`Authorization`, `Cookie`, `withCredentials`, etc.).\n\nHowever, when a child `HttpClient` delegates to a parent client via `withRequestsMadeViaParent()`, the child\u0027s `TransferCache` interceptor evaluates whether the request is eligible for caching **before** delegating to the parent client\u0027s interceptor chain. \n\nIf an outgoing request originates as anonymous from the child client, the child `TransferCache` marks the request as cacheable. When the request reaches a parent interceptor that injects sensitive authentication credentials (such as an `Authorization` header or API token), the parent `TransferCache` correctly skips caching the authenticated request. However, when the backend returns the private, authenticated response, the child `TransferCache` still stores the response in `TransferState` based on its initial pre-delegation evaluation.\n\n### Impact\n\nSuccessful exploitation allows sensitive, user-specific information belonging to an authenticated user to be leaked to unauthenticated or unauthorized users. This occurs when:\n\n1. During SSR, a child `HttpClient` initiates an unauthenticated request that is subsequently authenticated by a parent interceptor.\n2. The authenticated response body is cached into the SSR-rendered HTML page (`TransferState`).\n3. The rendered HTML page is stored by a shared caching layer (e.g., CDN, edge cache, or reverse proxy) or served across user sessions.\n4. Subsequent visitors requesting the same page receive the cached HTML containing the previous user\u0027s private data.\n\n### Attack Preconditions \u0026 Vulnerable Configurations\n\nAn application is affected only if **all** of the following conditions are met:\n\n* **SSR and Hydration Enabled:** The application uses Server-Side Rendering with hydration enabled (e.g., via `provideClientHydration()`).\n* **Hierarchical `HttpClient` with Delegation:** The application configures a child `HttpClient` using `withRequestsMadeViaParent()`.\n* **Parent-Level Authentication Injection:** Authentication credentials (such as `Authorization` headers, session cookies, or custom API tokens filtered via `withHttpTransferCacheOptions`) are attached by an interceptor in the **parent** injector chain rather than on the initial child request.\n* **Shared HTML Caching:** The SSR HTML responses are cached by a shared caching layer (CDN, reverse proxy, or application-level HTML cache).\n\n#### Vulnerable Code Pattern Example\n\n```ts\n// Parent Injector / Application Config\nexport const appConfig: ApplicationConfig = {\n  providers: [\n    provideHttpClient(\n      // Parent interceptor attaches sensitive Authorization header\n      withInterceptors([\n        (req, next) =\u003e next(req.clone({ setHeaders: { Authorization: `Bearer ${getToken()}` } }))\n      ])\n    ),\n  ],\n};\n\n// Child Injector / Feature or Component Config\nconst childClient = createEnvironmentInjector(\n  [\n    // Child delegates to parent; TransferCache evaluates req BEFORE parent auth interceptor runs\n    provideHttpClient(withRequestsMadeViaParent()),\n  ],\n  parentInjector\n).get(HttpClient);\n\n// Request originates without auth headers -\u003e marked cacheable by child TransferCache\nchildClient.get(\u0027/api/user/profile\u0027).subscribe();\n```\n\n### Patches\n\nThe issue is resolved by updating `@angular/common` to run root interceptors in the terminal request chain so that delegated clients leave inherited root interceptors to the parent chain, preventing duplicate execution and ensuring `HttpTransferCache` evaluates cache eligibility after parent request interceptors run.\n\n* `22.1.1`\n* `21.2.20`\n* `20.3.28`\n\n### Workarounds \u0026 Mitigations\n\nFor applications that cannot immediately upgrade to a patched version, use one of the following mitigations:\n\n1. **Attach Credentials Before or Within the Child Client:** Ensure authentication headers (e.g., `Authorization`) are attached directly when constructing the request or via an interceptor configured directly on the child `HttpClient`, rather than relying solely on parent interceptors.\n2. **Apply Explicit Cache Filters on the Child Client:** Configure `withHttpTransferCacheOptions` with a filter on the child client that explicitly excludes endpoints returning user-specific or sensitive data:\n   ```ts\n   provideClientHydration(\n     withHttpTransferCacheOptions({\n       filter: (req) =\u003e !req.url.includes(\u0027/api/private/\u0027),\n     })\n   )\n   ```\n3. **Disable HTTP Transfer Cache for Sensitive Routes:** If specific SSR routes handle user-authenticated data, disable transfer caching for those requests or ensure the SSR response sets `Cache-Control: no-store` / `private` headers at your edge/CDN layer so personalized HTML is never shared.",
  "id": "GHSA-p297-fm68-3q8c",
  "modified": "2026-09-10T20:19:20Z",
  "published": "2026-09-10T20:19:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/security/advisories/GHSA-p297-fm68-3q8c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/issues/69777"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/pull/69778"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/commit/c45028e44f5f3c1e0006eaccf86642deca51b2af"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/commit/caf616670fd20d528aa69e0131cc17d60f0cc27d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/commit/e4c416c20a1cb222ce73d29c035452b257380c56"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/angular/angular"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/releases/tag/v20.3.28"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/releases/tag/v21.2.20"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/releases/tag/v22.1.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Angular: Information Leak via `HttpTransferCache` Bypass When Using `withRequestsMadeViaParent`"
}

CVE-2026-88059 (GCVE-0-2026-88059)

Vulnerability from cvelistv5 – Published: 2026-09-10 19:00 – Updated: 2026-09-11 17:50

Title

Angular: Information Leak via `HttpTransferCache` Bypass When Using `withRequestsMadeViaParent`

Summary

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.28, 21.2.20, and 22.1.1, Angular's @angular/common HttpTransferCache can cache an authenticated response when Server-Side Rendering (SSR) and hydration use a hierarchical HttpClient configured with withRequestsMadeViaParent. The child TransferCache evaluates an initially anonymous request before delegation, then a parent withInterceptors chain adds an Authorization header, cookie, or API token; although the parent cache skips the authenticated request, the child still stores the private response in TransferState serialized as JSON in the ng-state script. Exploitation requires provideClientHydration, child provideHttpClient delegation through withRequestsMadeViaParent, parent-level credential injection, and an SSR HTML response shared across users by a CDN, reverse proxy, or application cache. A later unauthenticated or unauthorized visitor can receive the cached HTML containing the earlier authenticated user's sensitive response data. Applications can mitigate by attaching credentials at the child, filtering sensitive endpoints with withHttpTransferCacheOptions, disabling transfer caching for sensitive routes, or marking personalized HTML private or no-store. This issue is fixed in versions 20.3.28, 21.2.20, and 22.1.1.

Severity

4 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-11 17:49 UTC

CWE

CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
CWE-524 - Use of Cache Containing Sensitive Information

Assigner

GitHub_M mitre root

References

9 references

URL	Tags
https://github.com/angular/angular/security/advis…	x_refsource_CONFIRM
https://github.com/angular/angular/issues/69777	x_refsource_MISC
https://github.com/angular/angular/pull/69778	x_refsource_MISC
https://github.com/angular/angular/commit/c45028e…	x_refsource_MISC
https://github.com/angular/angular/commit/caf6166…	x_refsource_MISC
https://github.com/angular/angular/commit/e4c416c…	x_refsource_MISC
https://github.com/angular/angular/releases/tag/v…	x_refsource_MISC
https://github.com/angular/angular/releases/tag/v…	x_refsource_MISC
https://github.com/angular/angular/releases/tag/v22.1.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
angular	angular	Affected: <= 19.2.25 Affected: >= 20.0.0, < 20.3.28 Affected: >= 21.0.0, < 21.2.20 Affected: >= 22.0.0, < 22.1.1

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
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        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-88059",
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                    "Automatable": "no"
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                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-11T17:49:17.182667Z",
                "version": "2.0.3"
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        "providerMetadata": {
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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    "cna": {
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          "product": "angular",
          "vendor": "angular",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 19.2.25"
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              "status": "affected",
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            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.28, 21.2.20, and 22.1.1, Angular\u0027s @angular/common HttpTransferCache can cache an authenticated response when Server-Side Rendering (SSR) and hydration use a hierarchical HttpClient configured with withRequestsMadeViaParent. The child TransferCache evaluates an initially anonymous request before delegation, then a parent withInterceptors chain adds an Authorization header, cookie, or API token; although the parent cache skips the authenticated request, the child still stores the private response in TransferState serialized as JSON in the ng-state script. Exploitation requires provideClientHydration, child provideHttpClient delegation through withRequestsMadeViaParent, parent-level credential injection, and an SSR HTML response shared across users by a CDN, reverse proxy, or application cache. A later unauthenticated or unauthorized visitor can receive the cached HTML containing the earlier authenticated user\u0027s sensitive response data. Applications can mitigate by attaching credentials at the child, filtering sensitive endpoints with withHttpTransferCacheOptions, disabling transfer caching for sensitive routes, or marking personalized HTML private or no-store. This issue is fixed in versions 20.3.28, 21.2.20, and 22.1.1."
        }
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      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N",
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              "lang": "en",
              "type": "CWE"
            }
          ]
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        {
          "descriptions": [
            {
              "cweId": "CWE-524",
              "description": "CWE-524: Use of Cache Containing Sensitive Information",
              "lang": "en",
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          ]
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      "providerMetadata": {
        "dateUpdated": "2026-09-10T19:00:12.376Z",
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          "tags": [
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          "url": "https://github.com/angular/angular/commit/c45028e44f5f3c1e0006eaccf86642deca51b2af"
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          "tags": [
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        },
        {
          "name": "https://github.com/angular/angular/releases/tag/v21.2.20",
          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/angular/angular/releases/tag/v21.2.20"
        },
        {
          "name": "https://github.com/angular/angular/releases/tag/v22.1.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/angular/angular/releases/tag/v22.1.1"
        }
      ],
      "source": {
        "advisory": "GHSA-p297-fm68-3q8c",
        "discovery": "UNKNOWN"
      },
      "title": "Angular: Information Leak via `HttpTransferCache` Bypass When Using `withRequestsMadeViaParent`"
    }
  },
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    "cveId": "CVE-2026-88059",
    "datePublished": "2026-09-10T19:00:12.376Z",
    "dateReserved": "2026-09-09T21:22:45.434Z",
    "dateUpdated": "2026-09-11T17:50:22.562Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.