Summary
Description
An Open Redirect (CWE-601) vulnerability in Qwik City's default request handler middleware allows a remote attacker to redirect users to arbitrary protocol-relative URLs. Successful exploitation permits attackers to craft convincing phishing links that appear to originate from the trusted domain but redirect the victim to an attacker-controlled site. This affects qwik-city before version 1.19.0. This has been patched in qwik-city version 1.19.0.
Impact
Qwik City automatically applies the fixTrailingSlash middleware to page routes to ensure URL consistency. This vulnerability impacts all Qwik City applications deployed to runtimes that have a catch-all path to match arbitrary domains and that do not automatically normalize URL paths (e.g. Bun).
Exploitation allows an attacker to craft links that trigger a 301 redirect to arbitrary protocol-relative URLs. Browsers interpret this Location header as a protocol-relative URL, redirecting the user to attacker-controlled domains. This can enable phishing attacks and token theft among other common open redirect exploits.
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
This has been patched in qwik-city version 1.19.0. Users are strongly encouraged to update to the latest available release.
Frequently Asked Questions
- What is CVE-2026-25149? CVE-2026-25149 is a low-severity open redirect vulnerability in @builder.io/qwik-city (npm), affecting versions < 1.19.0. It is fixed in 1.19.0. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
- Which versions of @builder.io/qwik-city are affected by CVE-2026-25149? @builder.io/qwik-city (npm) versions < 1.19.0 is affected.
- Is there a fix for CVE-2026-25149? Yes. CVE-2026-25149 is fixed in 1.19.0. Upgrade to this version or later.
- Is CVE-2026-25149 exploitable, and should I be worried? Whether CVE-2026-25149 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-25149 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-25149? Upgrade
@builder.io/qwik-cityto 1.19.0 or later.