Summary
Craft Commerce: Coupon Code Brute-Force via Rate Limit Bypass
The CartController defines a RateLimiter behavior that is only activated when the 'number' POST/GET parameter is explicitly provided.
Details
When an attacker submits coupon codes against the session-based cart (without passing a 'number' parameter), no rate limiting is applied. This allows unlimited attempts to guess coupon codes.
Vulnerable Code
PoC
Complete instructions, including specific configuration details, to reproduce the vulnerability.
Impact
An attacker can enumerate all coupon codes through automated requests.
Remediation
Apply rate limiting unconditionally on actionUpdateCart regardless of whether 'number' is present.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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craftcms/commerce to 5.6.5 or later; craftcms/commerce to 4.11.2 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-55795? CVE-2026-55795 is a medium-severity security vulnerability in craftcms/commerce (composer), affecting versions >= 5.0.0, <= 5.6.4. It is fixed in 5.6.5, 4.11.2.
- Which versions of craftcms/commerce are affected by CVE-2026-55795? craftcms/commerce (composer) versions >= 5.0.0, <= 5.6.4 is affected.
- Is there a fix for CVE-2026-55795? Yes. CVE-2026-55795 is fixed in 5.6.5, 4.11.2. Upgrade to this version or later.
- Is CVE-2026-55795 exploitable, and should I be worried? Whether CVE-2026-55795 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55795 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55795?
- Upgrade
craftcms/commerceto 5.6.5 or later - Upgrade
craftcms/commerceto 4.11.2 or later
- Upgrade