Vulnerability-Lookup

GHSA-HQR9-C56F-3X7F

Vulnerability from github – Published: 2026-06-15 17:20 – Updated: 2026-07-15 22:05

Summary

@angular/platform-server: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Details

A Cross-Site Scripting (XSS) vulnerability exists in @angular/platform-server's DOM emulation dependency (domino) when serializing the content of raw-text elements (such as <script>, <style>, and <iframe>).

domino supports escaping raw-text elements during serialization to prevent closing-tag breakout. However, a Unicode index alignment bug existed in this escaping logic.

In JavaScript, string lengths and character indices are calculated based on UTF-16 code units (where astral characters—such as emojis—occupy 2 code units / 4 bytes). If the bound dynamic text contained astral Unicode characters before the closing tag (e.g. </script>, </style>, or </iframe>), the index offset calculation in domino's replacement logic shifted.

This misalignment caused domino to fail to replace or escape the closing tag, leaving it raw and unescaped in the output HTML.

An attacker who controls the dynamic text can supply a payload containing both an astral Unicode character and a closing tag (e.g., 😀</iframe><script>alert(1)</script>). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent <script> block, leading to same-origin Cross-Site Scripting (XSS).

Impact

This vulnerability allows an attacker to perform same-origin Cross-Site Scripting (XSS) attacks against any user visiting an SSR-rendered page that binds user-controlled data inside raw-text elements. This can lead to session hijacking, credentials theft, unauthorized actions on behalf of users, and defacement.

Patched Versions

22.0.0-rc.2
21.2.16
20.3.24
19.2.25

Workarounds

If you cannot immediately update your dependencies, you can:

Avoid binding user-controlled values inside <iframe> or other raw-text elements.
Sanitize any user input placed inside raw-text elements to explicitly strip closing tags before passing it to the template.

Severity

6.1 (Medium)


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

8.6 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/platform-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "22.0.0-next.0"
            },
            {
              "fixed": "22.0.0-rc.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/platform-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "21.0.0-next.0"
            },
            {
              "fixed": "21.2.16"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/platform-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "20.0.0-next.0"
            },
            {
              "fixed": "20.3.24"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/platform-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "19.0.0-next.0"
            },
            {
              "fixed": "19.2.25"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@angular/platform-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "18.2.14"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50555"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-15T17:20:30Z",
    "nvd_published_at": "2026-06-22T18:16:43Z",
    "severity": "HIGH"
  },
  "details": "A Cross-Site Scripting (XSS) vulnerability exists in `@angular/platform-server`\u0027s DOM emulation dependency (`domino`) when serializing the content of raw-text elements (such as `\u003cscript\u003e`, `\u003cstyle\u003e`, and `\u003ciframe\u003e`).\n\n`domino` supports escaping raw-text elements during serialization to prevent closing-tag breakout. However, a **Unicode index alignment bug** existed in this escaping logic.\n\nIn JavaScript, string lengths and character indices are calculated based on UTF-16 code units (where astral characters\u2014such as emojis\u2014occupy 2 code units / 4 bytes). If the bound dynamic text contained astral Unicode characters _before_ the closing tag (e.g. `\u003c/script\u003e`, `\u003c/style\u003e`, or `\u003c/iframe\u003e`), the index offset calculation in `domino`\u0027s replacement logic shifted.\n\nThis misalignment caused `domino` to fail to replace or escape the closing tag, leaving it raw and unescaped in the output HTML.\n\nAn attacker who controls the dynamic text can supply a payload containing both an astral Unicode character and a closing tag (e.g., `\ud83d\ude00\u003c/iframe\u003e\u003cscript\u003ealert(1)\u003c/script\u003e`). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent `\u003cscript\u003e` block, leading to same-origin Cross-Site Scripting (XSS).\n\n### Impact\n\nThis vulnerability allows an attacker to perform same-origin Cross-Site Scripting (XSS) attacks against any user visiting an SSR-rendered page that binds user-controlled data inside raw-text elements. This can lead to session hijacking, credentials theft, unauthorized actions on behalf of users, and defacement.\n\n### Patched Versions\n\n- 22.0.0-rc.2\n- 21.2.16\n- 20.3.24\n- 19.2.25\n\n### Workarounds\n\nIf you cannot immediately update your dependencies, you can:\n\n- Avoid binding user-controlled values inside `\u003ciframe\u003e` or other raw-text elements.\n- Sanitize any user input placed inside raw-text elements to explicitly strip closing tags before passing it to the template.",
  "id": "GHSA-hqr9-c56f-3x7f",
  "modified": "2026-07-15T22:05:58Z",
  "published": "2026-06-15T17:20:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/angular/angular/security/advisories/GHSA-hqr9-c56f-3x7f"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50555"
    },
    {
      "type": "WEB",
      "url": "https://github.com/angular/domino/pull/29"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/angular/angular"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "@angular/platform-server: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)"
}

CVE-2026-50555 (GCVE-0-2026-50555)

Vulnerability from cvelistv5 – Published: 2026-06-22 15:37 – Updated: 2026-06-22 17:58

Title

Angular: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in @angular/platform-server

Summary

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25, a Cross-Site Scripting (XSS) vulnerability exists in @angular/platform-server's DOM emulation dependency (domino) when serializing the content of raw-text elements (such as <script>, <style>, and <iframe>). domino supports escaping raw-text elements during serialization to prevent closing-tag breakout. However, a Unicode index alignment bug existed in this escaping logic. In JavaScript, string lengths and character indices are calculated based on UTF-16 code units (where astral characters—such as emojis—occupy 2 code units / 4 bytes). If the bound dynamic text contained astral Unicode characters before the closing tag (e.g. </script>, </style>, or </iframe>), the index offset calculation in domino's replacement logic shifted. This misalignment caused domino to fail to replace or escape the closing tag, leaving it raw and unescaped in the output HTML. An attacker who controls the dynamic text can supply a payload containing both an astral Unicode character and a closing tag (e.g., 😀</iframe><script>alert(1)</script>). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent <script> block, leading to same-origin Cross-Site Scripting (XSS). This vulnerability is fixed in 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25.

Severity

8.6 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-22 17:56 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7831 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/angular/angular/security/advis…	x_refsource_CONFIRM
https://github.com/angular/domino/pull/29	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
angular	angular	Affected: >= 22.0.0-next.0, < 22.0.0-rc.2 Affected: >= 21.0.0-next.0, < 21.2.16 Affected: >= 20.0.0-next.0, < 20.3.24 Affected: >= 19.0.0-next.0, < 19.2.25 Affected: <= 18.2.14

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
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                "id": "CVE-2026-50555",
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                  {
                    "Exploitation": "none"
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                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
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                "role": "CISA Coordinator",
                "timestamp": "2026-06-22T17:56:51.469447Z",
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          "shortName": "CISA-ADP"
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    "cna": {
      "affected": [
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          "product": "angular",
          "vendor": "angular",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 22.0.0-next.0, \u003c 22.0.0-rc.2"
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              "status": "affected",
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            {
              "status": "affected",
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        }
      ],
      "descriptions": [
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          "lang": "en",
          "value": "Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25, a Cross-Site Scripting (XSS) vulnerability exists in @angular/platform-server\u0027s DOM emulation dependency (domino) when serializing the content of raw-text elements (such as \u003cscript\u003e, \u003cstyle\u003e, and \u003ciframe\u003e). domino supports escaping raw-text elements during serialization to prevent closing-tag breakout. However, a Unicode index alignment bug existed in this escaping logic. In JavaScript, string lengths and character indices are calculated based on UTF-16 code units (where astral characters\u2014such as emojis\u2014occupy 2 code units / 4 bytes). If the bound dynamic text contained astral Unicode characters before the closing tag (e.g. \u003c/script\u003e, \u003c/style\u003e, or \u003c/iframe\u003e), the index offset calculation in domino\u0027s replacement logic shifted. This misalignment caused domino to fail to replace or escape the closing tag, leaving it raw and unescaped in the output HTML. An attacker who controls the dynamic text can supply a payload containing both an astral Unicode character and a closing tag (e.g., \ud83d\ude00\u003c/iframe\u003e\u003cscript\u003ealert(1)\u003c/script\u003e). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent \u003cscript\u003e block, leading to same-origin Cross-Site Scripting (XSS). This vulnerability is fixed in 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25."
        }
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            "subConfidentialityImpact": "NONE",
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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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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