CVE-2026-54159

prestashop/ps_facetedsearch: PHP Object Injection in faceted search cache allows unauthenticated RCE

A PHP Object Injection vulnerability affects the PrestaShop module ps_facetedsearch.

The module rebuilds the selected search filters from the request URL. The value of a slider filter (price or weight) is taken from the URL without sufficient validation, then stored in an internal filter-block cache where it is serialized and later read back with a raw native unserialize().
By crafting that value, an attacker can smuggle a malicious serialized PHP object into the cache. When it is deserialized, a gadget chain writes an arbitrary PHP file inside the module directory, which is then used as a webshell to run commands on the server.

CVE-2026-54159 has a CVSS score of 10.0 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.0.4); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Upgrade the ps_facetedsearch module to the patched version. Upgrading the module is the best action that removes the vulnerability.

Otherwise, you can apply the fix manually in the file src/Filters/Block.php:

In the getFromCache() method, replace the native unserialize() call:

// Before
if (!empty($row)) {
    return unserialize(current($row));
}

// After
if (!empty($row)) {
    return \Tools::unSerialize(current($row));
}

1. What is CVE-2026-54159? CVE-2026-54159 is a critical-severity security vulnerability in prestashop/ps_facetedsearch (composer), affecting versions >= 3.0.0, < 4.0.4. It is fixed in 4.0.4.
2. How severe is CVE-2026-54159? CVE-2026-54159 has a CVSS score of 10.0 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of prestashop/ps_facetedsearch are affected by CVE-2026-54159? prestashop/ps_facetedsearch (composer) versions >= 3.0.0, < 4.0.4 is affected.
4. Is there a fix for CVE-2026-54159? Yes. CVE-2026-54159 is fixed in 4.0.4. Upgrade to this version or later.
5. Is CVE-2026-54159 exploitable, and should I be worried? Whether CVE-2026-54159 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
6. What actually determines whether CVE-2026-54159 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.
7. How do I fix CVE-2026-54159? Upgrade prestashop/ps_facetedsearch to 4.0.4 or later.

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