Angular up to 18.2.14/19.2.24/20.3.23/21.2.15 Unicode Character cross site scripting

Summaryinfo

A vulnerability marked as problematic has been reported in Angular up to 18.2.14/19.2.24/20.3.23/21.2.15. Affected is an unknown function of the component Unicode Character Handler. Performing a manipulation results in cross site scripting. This vulnerability is cataloged as CVE-2026-50555. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Angular up to 18.2.14/19.2.24/20.3.23/21.2.15. This affects an unknown code of the component Unicode Character Handler. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

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 , , and ). 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. , , or ), 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., ????alert(1)). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent 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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-50555 since 06/04/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 19.2.25, 20.3.24, 21.2.16 or 22.0.0-rc.2 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-38289). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• JavaScript Library

Name

• Angular

Version

• 18.2.0
• 18.2.1
• 18.2.2
• 18.2.3
• 18.2.4
• 18.2.5
• 18.2.6
• 18.2.7
• 18.2.8
• 18.2.9
• 18.2.10
• 18.2.11
• 18.2.12
• 18.2.13
• 18.2.14
• 19.2.0
• 19.2.1
• 19.2.2
• 19.2.3
• 19.2.4
• 19.2.5
• 19.2.6
• 19.2.7
• 19.2.8
• 19.2.9
• 19.2.10
• 19.2.11
• 19.2.12
• 19.2.13
• 19.2.14
• 19.2.15
• 19.2.16
• 19.2.17
• 19.2.18
• 19.2.19
• 19.2.20
• 19.2.21
• 19.2.22
• 19.2.23
• 19.2.24
• 20.3.0
• 20.3.1
• 20.3.2
• 20.3.3
• 20.3.4
• 20.3.5
• 20.3.6
• 20.3.7
• 20.3.8
• 20.3.9
• 20.3.10
• 20.3.11
• 20.3.12
• 20.3.13
• 20.3.14
• 20.3.15
• 20.3.16
• 20.3.17
• 20.3.18
• 20.3.19
• 20.3.20
• 20.3.21
• 20.3.22
• 20.3.23
• 21.2.0
• 21.2.1
• 21.2.2
• 21.2.3
• 21.2.4
• 21.2.5
• 21.2.6
• 21.2.7
• 21.2.8
• 21.2.9
• 21.2.10
• 21.2.11
• 21.2.12
• 21.2.13
• 21.2.14
• 21.2.15

Website

• Product: https://github.com/angular/angular/

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