CVE-2026-41687 — MEDIUM (4.3)

Vulnerability 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.

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-918

References

FAQ

What is CVE-2026-41687?

CVE-2026-41687 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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) ...

How severe is CVE-2026-41687?

CVE-2026-41687 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-41687?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.