CVE-2026-49456 Waku: Open Redirect via `unstable_redirect` Helper
Attackers can redirect users to malicious sites via the unstable_redirect helper, enabling phishing and credential theft in Waku applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-49456?
CVE-2026-49456 is a low-severity vulnerability in wakujs waku, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Waku is the minimal React framework. Prior to version 1.0.0-beta.1, the unstable_redirect() helper exported from waku/router/server (packages/waku/src/router/define-router.tsx:156–161) accepts an arbitrary string and reflects it unchanged into the HTTP Location response header with no URL validation, scheme restriction, or path-only enforcement. Any application that passes user-controlled input to this helper — the natural pattern documented in the JSDoc and official fixtures — is vulnerable to open redirect attacks. An attacker who convinces a victim to click a crafted link can silently redirect the browser to an arbitrary external domain, enabling phishing, credential harvesting, and OAuth token theft. Additionally, scheme-relative URLs (//evil.example/) bypass naive https?://-only allow-list filters that developers might add as ad-hoc mitigations. This issue has been patched in version 1.0.0-beta.1.
Weakness: CWE-601
Which versions are affected by CVE-2026-49456?
2 open source packages ship an affected version, including waku.
| Package | Affected | Fixed in |
|---|---|---|
waku npm | All versions | 1.0.0-beta.1 |
waku npm | All versions | 1.0.0-beta.1 |
How do I fix CVE-2026-49456?
Upgrade waku to 1.0.0-beta.1 or later.
Is CVE-2026-49456 being exploited?
There is no known exploitation of CVE-2026-49456 in the wild and no public exploit code.
Sources
Also known as GHSA-43fc-v873-qw85.