J2Store extension for Joomla: Improper Neutralization of Input During Web Page Generation
CVE-2026-74252 is a high-severity improper neutralization of input during web page generation vulnerability in J2Store extension for Joomla from J2commerce.com, with a CVSS 4.0 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected J2Store extension for Joomla versions: 1.0.0-3.3.20; 4.0.0-4.0.20; 4.1.0-4.1.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.52% 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.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| J2commerce.com | J2Store extension for Joomla | 1.0.0-3.3.20; 4.0.0-4.0.20; 4.1.0-4.1.5 | 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
- ActiveA user must deliberately do something unusual, such as dismissing a warning.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- LowLimited 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:A/VC:H/VI:H/VA:L/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 - Stored XSS in Guest checkout in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - J2Commerce 4.1.5 is vulnerable to Stored Cross-Site Scripting (XSS) through the guest checkout billing address fields. An unauthenticated attacker exploits a filter bypass in Joomla's Input::getArray() combined with PHP's variables_order=EGPCS (Cookie overrides POST in $_REQUEST ) to store unsanitized HTML in fields such as billing_first_name.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Input During Web Page Generation
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
- Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in J2Store extension for Joomla
- 8.7 High severity
- 8.7 High severity
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- 7.1 High severity
- 9.5 Critical severity
- 7.1 High severity
Recent Improper Neutralization of Input During Web Page Generation vulnerabilities
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- 8.0 High severity
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