CVE-2026-41687 Wallos: SSRF CGNAT Bypass in subscription/payments Logo URL — is_cgnat_ip() Not Used in Inline Checks
Authenticated users can bypass SSRF protections to access internal services in CGNAT environments via logo URL fields.
- 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-2026-41687?
CVE-2026-41687 is a medium-severity server-side request forgery vulnerability in ellite Wallos, published on 7 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.8.1, the SSRF protection in endpoints/subscription/add.php (line 42) and endpoints/payments/add.php (line 40) uses an inline IP validation check (FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) that does not block CGNAT addresses (100.64.0.0/10, RFC 6598). The includes/ssrf_helper.php file explicitly defines is_cgnat_ip() to cover this gap (used by notification endpoints), but the logo/icon URL fetching in subscription and payment endpoints performs its own inline validation that misses this range. This allows authenticated users to perform Blind SSRF to internal services in Tailscale, Carrier-Grade NAT, and other environments using 100.64.0.0/10 addresses. This issue has been patched in version 4.8.1.
Weakness: CWE-918
Which versions are affected by CVE-2026-41687?
How do I fix CVE-2026-41687?
No fix has been published for CVE-2026-41687 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-2026-41687 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41687 exists.
Sources
Also known as GHSA-4v59-hghw-7gc2.