CVE-2026-81567: J2Store Joomla Extension SQL Injection Flaw

CVE-2026-81567 Overview

CVE-2026-81567 is an unauthenticated blind SQL injection vulnerability in the J2Store extension for Joomla, developed by j2commerce.com. The flaw resides in the storefront product list and product-tags filter functionality. Attackers can extract arbitrary database content, including customer records, order data, and stored credentials or tokens, using boolean-based or time-based inference techniques. The vulnerability affects J2Store versions 1.0.0-3.3.2, 4.0.0-4.0.22, and 4.1.0-4.1.7. Exploitation requires no authentication and can be executed remotely against any public storefront exposing the standard product listing.

Critical Impact
Unauthenticated remote attackers can extract arbitrary database contents from affected Joomla storefronts, including customer PII, order history, and stored authentication material.

Affected Products

J2Store 1.0.0 through 3.3.2
J2Store 4.0.0 through 4.0.22
J2Store 4.1.0 through 4.1.7

Discovery Timeline

2026-09-15 - CVE-2026-81567 published to NVD
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-81567

Vulnerability Analysis

The vulnerability is a blind SQL injection flaw [CWE-89] in the J2Store Joomla extension. The storefront product list and product-tags filter accept user-controlled input that is concatenated into SQL queries without proper parameterization or sanitization. Because the injection is blind, attackers infer database contents by observing conditional responses or measured response delays rather than direct output.

Exploitation targets the public product listing endpoint, which does not require authentication or user interaction. An attacker can iteratively enumerate database schema, table contents, and sensitive fields such as customer profiles, transaction records, and stored session tokens. The attack has network reach and low complexity, making it viable for opportunistic scanning against Joomla sites running J2Store.

The EPSS score is 0.228% at the 13.67 percentile as of 2026-09-16, indicating a currently low modeled probability of exploitation activity. However, blind SQLi in publicly reachable e-commerce endpoints historically attracts automated scanning once proof-of-concept tooling emerges.

Root Cause

The root cause is improper neutralization of special elements used in an SQL command. Filter parameters exposed on the storefront product listing are interpolated directly into SQL statements. The J2Store code path handling product-tags filtering fails to enforce parameterized queries or apply strict allow-list validation on input values.

Attack Vector

The attack vector is remote over the network with no privileges and no user interaction required. An attacker sends crafted HTTP requests to the storefront product list or product-tags filter endpoint. Payloads use boolean predicates or time-delay functions such as SLEEP() to infer query results one bit at a time. Any publicly accessible Joomla site running an affected J2Store version is reachable.

No public proof-of-concept has been published at the time of this advisory. Refer to the J2 Commerce vendor site for official technical details and remediation guidance.

Detection Methods for CVE-2026-81567

Indicators of Compromise

HTTP requests to storefront product listing or product-tags filter URLs containing SQL syntax such as UNION, SELECT, SLEEP(, BENCHMARK(, or boolean tautologies like AND 1=1.
Unusually long response times on product listing endpoints, consistent with time-based blind SQLi inference.
High-volume, low-variance request patterns from a single source targeting com_j2store components or product-tag query parameters.
Web server logs showing repeated 200 responses on product-list URLs with incrementally varying single-character payloads.

Detection Strategies

Deploy web application firewall rules that detect SQL keywords and time-delay functions in query parameters of J2Store endpoints.
Enable database query logging and alert on queries containing filter values with SQL metacharacters or SLEEP/BENCHMARK calls.
Correlate spikes in average response time on product listing URLs with source IP request volume to identify time-based inference.

Monitoring Recommendations

Monitor Joomla and J2Store version metadata across managed sites to identify installations within the vulnerable version ranges.
Track outbound anomalies from database servers hosting J2Store data, including unexpected large SELECT operations on customer or credential tables.
Alert on repeated 4xx or 5xx errors originating from J2Store storefront endpoints, which often accompany payload tuning during exploitation.

How to Mitigate CVE-2026-81567

Immediate Actions Required

Identify all Joomla sites running J2Store versions 1.0.0-3.3.2, 4.0.0-4.0.22, or 4.1.0-4.1.7 and prioritize them for remediation.
Apply the vendor-supplied security update from j2commerce.com as soon as it is available for your version branch.
Rotate database credentials, API tokens, and customer session secrets stored in the J2Store database if exploitation is suspected.
Force customer password resets if there is any evidence of unauthorized SELECT activity against user tables.

Patch Information

Refer to the J2 Commerce vendor site for the current fixed release for each affected branch. Upgrade to the vendor-designated fixed version above 3.3.2, 4.0.22, and 4.1.7 respectively. Verify the update through the Joomla Extensions Manager and confirm the installed version after patching.

Workarounds

Restrict access to storefront product listing and product-tags filter endpoints using WAF rules that block SQL syntax and time-delay functions in query parameters.
Temporarily disable the J2Store component through the Joomla Extension Manager if the site is not actively used for commerce.
Enforce request rate limiting on com_j2store URLs to slow automated blind inference attacks.
Enable database-level query timeouts to reduce the effectiveness of time-based SQLi payloads.

bash

# Example WAF rule fragment (ModSecurity) to block common blind SQLi patterns
# on J2Store storefront endpoints
SecRule REQUEST_URI "@contains com_j2store" \
    "chain,phase:2,deny,status:403,id:1026815670,\
    msg:'Possible J2Store SQLi attempt (CVE-2026-81567)'"
    SecRule ARGS "@rx (?i)(union\s+select|sleep\s*\(|benchmark\s*\(|--\s|/\*|\bor\b\s+1=1)" \
        "t:none,t:urlDecodeUni"