CVE-2026-73629 Serendipity before 2.6.0 SSRF via hex IPv4 and IPv6 addresses
Authenticated users can bypass URL filters to access internal services and retrieve data via the uploads directory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73629?
CVE-2026-73629 is a high-severity server-side request forgery vulnerability in s9y Serendipity, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Serendipity before 2.6.0 contains a server-side request forgery vulnerability in the serendipity_url_allowed() filter that fails to block hex-encoded IPv4 addresses, IPv6 literals, and link-local ranges. Authenticated users with adminImagesAdd permission can bypass the filter using alternate address formats to request internal services and retrieve response bodies through the public uploads directory.
Weakness: CWE-918
Which versions are affected by CVE-2026-73629?
How do I fix CVE-2026-73629?
No fix has been published for CVE-2026-73629 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-73629 being exploited?
There is no known exploitation of CVE-2026-73629 in the wild and no public exploit code.
Sources
Also known as GHSA-2m48-gjj5-5x86, GHSA-fh9h-cxrw-2xj2.