CVE-2026-50198

Wallos: Cross-user subscription cost inference via replacement_subscription_id

MEDIUM
4.3
CVSS Score
Published: August 31, 2026 at 08:25 PM UTC
Updated: September 8, 2026 at 09:29 PM UTC
1 product affected across 1 vendorWallos

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.9.1, an authenticated user can edit their own inactive subscription and set replacement_subscription_id to a subscription ID belonging to another user. The write is accepted, and later the stats logic dereferences that foreign subscription ID without user_id scoping. This lets the attacker infer the victim subscription's monthly-normalized cost by observing changes in their own stats output. This does not expose the full victim subscription object, but it does expose derived financial metadata. This issue has been patched in version 4.9.1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.9.1
Affected range stops below 4.9.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-639

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