J2Store extension for Joomla: Authorization Bypass Through User-Controlled Key
CVE-2026-78064 is a high-severity authorization bypass through user-controlled key vulnerability in J2Store extension for Joomla from J2commerce.com, with a CVSS 4.0 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected J2Store extension for Joomla versions: 1.0.0-3.3.21; 4.0.0-4.0.21; 4.1.0-4.1.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.41% 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 J2Store extension for Joomla you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| J2commerce.com | J2Store extension for Joomla | 1.0.0-3.3.21; 4.0.0-4.0.21; 4.1.0-4.1.6 | Not stated |
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.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- LowLimited loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- NoneNo loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (joomla.org).
Official description
Joomla Extension - j2commerce.com - Anonymous cart-record tampering via inherited FOF `save` task in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - `fof.xml` grants the `carts` view's tasks a wildcard `true` ACL, and FOF only enforces CSRF tokens on back-end HTML requests, not on front-end `format=raw` requests. `J2StoreControllerCarts` already scoped `remove()` to the caller's own session, but never overrode the generic FOF `save` task, so it remained reachable to insert new cart rows with an attacker-chosen `user_id`/`session_id`, or overwrite an existing row by id.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authorization Bypass Through User-Controlled Key
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How developers prevent this class of flaw
- For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
- Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
References
Other references
Other vulnerabilities in J2Store extension for Joomla
- 8.7 High severity
- 8.7 High severity
- 8.7 High severity
- 7.1 High severity
- 9.5 Critical severity
- 7.1 High severity
Recent Authorization Bypass Through User-Controlled Key vulnerabilities
- 10.0 Critical severity
- 8.1 High severity
- 7.7 High severity
- 7.5 High severity
- 7.7 High severity
- 7.7 High severity
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