Cyber Resilience

CVE-2026-33399

SSRF in Wallosapp Wallos ≤ 4.7.0

Public PoCSSRF
Published
24 March 2026
Modified
26 March 2026
Patch / advisory
CVSS Score v3.1 7.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
EPSS Score 0.0028 21th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2026-33399 is a high-severity SSRF (CWE-918) vulnerability in Wallosapp Wallos. Its CVSS base score is 7.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-33399 is a server-side request forgery (SSRF) vulnerability affecting Wallos, an open-source, self-hostable personal subscription tracker, in versions prior to 4.7.0. It stems from an incomplete fix for previous SSRF issues (CVE-2026-30839 and CVE-2026-30840) implemented in version 4.6.2. While the validate_webhook_url_for_ssrf() protection was added to test* notification endpoints, it was not applied to the corresponding save* endpoints. This allows an authenticated user to save an internal or private IP address as a notification URL. When the cron job sendnotifications.php executes, it sends a request to that internal IP without SSRF validation. The vulnerability is rated 7.7 on the CVSS 3.1 scale (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N) and maps to CWE-918: Server-Side Request Forgery.

An authenticated user with low privileges can exploit this by submitting a malicious internal or private IP address via the save* notification endpoints. No user interaction is required beyond authentication, and exploitation occurs automatically when the sendnotifications.php cron job runs, forging requests from the server to arbitrary internal services. Attackers can achieve high-impact confidentiality violations by tricking the Wallos server into accessing and potentially leaking data from internal networks, with the changed scope amplifying the effect across security boundaries.

The GitHub security advisory (GHSA-mfjc-3258-cq3j) and the patching commit (e87387f0ebb540cd33e6dfda7181db9db650ecef) confirm that the issue is fully addressed in Wallos version 4.7.0, where SSRF validation is extended to the save* endpoints. Security practitioners should upgrade to 4.7.0 or later and review cron job configurations to mitigate exposure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.7.0, the SSRF fix applied in version 4.6.2 for CVE-2026-30839 and CVE-2026-30840 is incomplete. The validate_webhook_url_for_ssrf() protection was added to the test* notification endpoints but not to the corresponding…

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save* endpoints. An authenticated user can save an internal/private IP address as a notification URL, and when the cron job sendnotifications.php executes, the request is sent to the internal IP without any SSRF validation. This issue has been patched in version 4.7.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-30839Same product: Wallosapp Wallos
CVE-2026-27479Same product: Wallosapp Wallos
CVE-2026-33401Same product: Wallosapp Wallos
CVE-2024-29320Same product: Wallosapp Wallos
CVE-2026-30840Same product: Wallosapp Wallos
CVE-2026-33407Same product: Wallosapp Wallos
CVE-2026-30828Same product: Wallosapp Wallos
CVE-2024-55371Same product: Wallosapp Wallos
CVE-2024-55372Same product: Wallosapp Wallos
CVE-2024-57386Same product: Wallosapp Wallos

Affected Assets

wallosapp
wallos
≤ 4.7.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.

Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.

Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References