Wallos: Server-Side Request Forgery
CVE-2026-33399 is a high-severity server-side request forgery vulnerability in Wallos from Ellite, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Wallos versions: < 4.7.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Wallos you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N. Scored by CNA (github.com).
Official description
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 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Server-Side Request Forgery
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
How developers prevent this class of flaw
- If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
- If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in Wallos
- 8.2 High severity
- 8.1 High severity
- 8.5 High severity
- 8.5 High severity
- 8.2 High severity
- 8.2 High severity
Recent Server-Side Request Forgery vulnerabilities
- 9.1 Critical severity
- 7.4 High severity
- 7.3 High severity
- 8.2 High severity
- 8.6 High severity
- 9.1 Critical severity
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