CriticalCVE-2026-45247

    Mirasvit Cache Warmer for Magento < 1.11.12 PHP Object Injection (CVE-2026-45247)

    Published In CISA KEV since Sources: SingCERT, CVE.org, EUVD

    What is affected, what to do

    Mirasvit Full Page Cache Warmer for Magento 2 before version 1.11.12 contains a PHP object injection vulnerability that allows unauthenticated attackers to achieve remote code execution by supplying a crafted serialized PHP object in the CacheWarmer cookie. Attackers can exploit the unrestricted call to PHP's native unserialize() function combined with gadget chains available in Magento and its dependencies to execute arbitrary code on the server.

    The vulnerability is being actively exploited; treat it as a priority. Update Mirasvit Full Page Cache Warmer for Magento 2 to version 1.11.12. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Mirasvit Full Page Cache Warmer for Magento 2 lt *..1.11.12
    Fixed in
    • Mirasvit Full Page Cache Warmer for Magento 2 1.11.12

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: SingCERT, CVE.org, EUVD

    26.2 %

    EPSS score

    Elevated — model estimates 10-50% exploitation likelihood.

    Source: FIRST EPSS, percentile 98.0

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    243.65 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: VulnCheck KEV (opens in a new tab), CSA/SingCERT How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.8
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.3
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    26.2 %
    Elevated — model estimates 10-50% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    98.0
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 3 June 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-502

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This CVE combines pre-authentication remote code execution via a trivially controllable cookie value with the broad attack surface of Magento e-commerce shops — exactly the profile that Magecart and card-skimming crews have systematically weaponised for years to siphon payment data. Unauthenticated network reachability (CVSS vector AV:N/PR:N/UI:N) and the availability of public Magento gadget chains make working exploits easy to source; the CISA KEV listing confirms active exploitation. Treat as priority 1 for any shop running the Mirasvit module with internet exposure — even without the ransomware flag, the reputational and PCI DSS fallout from a payment-environment breach is existential. Patch SLA: 24-48 hours.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Upgrade Mirasvit Full Page Cache Warmer for Magento 2 to version 1.11.12 or later without delay — this is the vendor-supplied patch release that removes the unsafe unserialize() call path.
      • Until the patch is deployed, block or strip any inbound HTTP request carrying the CacheWarmer cookie at the upstream reverse proxy, WAF, or load balancer (nginx, Apache, Cloudflare, F5). Rule shape: if the Cookie header contains CacheWarmer=, drop the request or remove the cookie before it reaches Magento.
      • Inventory all Magento installations (bin/magento module:status | grep -i Mirasvit, composer show | grep mirasvit) and patch internet-facing shops first; do not overlook staging and development environments if they are reachable from the WAN.
      • Inspect the PHP process user (typically www-data, nginx, php-fpm) for newly spawned shells, outbound connections, and new files beneath pub/, var/, generated/. Any hit triggers full incident response and host isolation.
      • Rotate admin session tokens, integration API keys, database credentials, and stored payment-gateway secrets if compromise is even suspected — RCE on a Magento backend usually equals full access to customer and payment data flows.

    2. Runbook step 2

      Mitigation layers

      • WAF rule (ModSecurity shape): SecRule REQUEST_COOKIES:CacheWarmer "@rx .+" "id:2026045247,phase:1,deny,status:403,log,msg:'CVE-2026-45247 CacheWarmer cookie blocked'". In Cloudflare or AWS WAF, express the same logic as a custom cookie-name rule.
      • Network segmentation: restrict Magento backend egress to a strict allowlist (payment provider, SMTP relay, package mirrors). Enforce the policy at the perimeter firewall to defeat reverse shells and second-stage downloads.
      • Endpoint hardening: extend disable_functions in php.ini with exec, system, passthru, shell_exec, proc_open, popen, pcntl_exec; constrain open_basedir to the Magento document root. This neutralises common gadget-chain payloads.
      • IAM and least privilege: run the PHP-FPM pool under a dedicated low-privilege account, no sudo, no runtime write access to app/etc/env.php; audit filesystem permissions against the Magento Security Hardening Guide.
      • Configuration: temporarily disable the module if the patch cannot be rolled out immediately — bin/magento module:disable Mirasvit_CacheWarmer && bin/magento setup:upgrade, then flush caches.
      • Enable file integrity monitoring (AIDE, Tripwire, Wazuh) on pub/, app/code/, generated/code/ — PHP object-injection attacks typically drop webshells into these paths.

    3. Runbook step 3

      Detection rules

      • Web access logs: hunt for requests whose Cookie: CacheWarmer= value URL-decodes to a string starting with O: or a: (PHP serialised-object magic). SPL shape: index=web sourcetype=nginx:access cookie="*CacheWarmer=O*" OR cookie="*CacheWarmer=a*".
      • Sigma shape (process ancestry via Sysmon or EDR): parent_image endswith '\php-fpm' OR endswith '/php-fpm' combined with image in ('/bin/sh','/bin/bash','/usr/bin/curl','/usr/bin/wget','/usr/bin/python*') — the classic RCE spawn pattern from a web-server context.
      • Linux auditd: watch execve where uid=www-data and comm in (sh,bash,nc,curl,wget,perl,python3). Rule: -a always,exit -F arch=b64 -S execve -F auid=33 -k magento_rce (adjust UID).
      • Network telemetry (Zeek/Suricata): new outbound TCP connections from the Magento host to non-allowlisted IPs, especially on ports 4444, 1337, 8080, 9001, or DNS-tunnelling patterns. Keep Suricata ET-Shellcode and ET-Trojan categories enabled.
      • File integrity: alert on any new .php file beneath pub/media/, pub/static/, var/ — these directories should never contain executable PHP in normal operation.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    Mirasvit Full Page Cache Warmer for Magento 2 before version 1.11.12 contains a PHP object injection vulnerability that allows unauthenticated attackers to achieve remote code execution by supplying a crafted serialized PHP object in the CacheWarmer cookie. Attackers can exploit the unrestricted call to PHP's native unserialize() function combined with gadget chains available in Magento and its dependencies to execute arbitrary code on the server.

    Source: CSA/SingCERT, cvelistv5, CISA KEV Catalog, NVD (NIST), CVE.org (MITRE), ENISA EUVD

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    MirasvitFull Page Cache Warmer for Magento 2
    • < 1.11.12
    • 1.11.12
    mirasvitfull_page_cache_warmer
    • < 1.11.12
    • 1.11.12

    Weakness classes (CWE)

    • CWE-502Deserialization of Untrusted Data

      Base

      The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

      Entry at MITRE CWE-502

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    CSA/SingCERTCritical Vulnerability in Mirasvit Full Page Cache Warmer for Magento 2 (opens in a new tab)CSA/SingCERTactively exploited
    PoC-in-GitHub (nomi-sec)PoC-Funcional---CVE-2026-45247-Mirasvit-Full-Page-Cache-Warmer-RCE- (opens in a new tab)github.comPoC (publicly reported)reported, not verified
    PoC-in-GitHub (nomi-sec)CVE-2026-45247 (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

    • sansec.ioresearch/mirasvit-cache-warmer-object-injectionTechnical description
    • mirasvit.compackage/changelog/?package=mirasvit/module-cache-warmerRelease notes, Patch
    • vulncheck.comadvisories/mirasvit-cache-warmer-for-magento-php-object-injecti…Third-party advisory
    • imperva.comblog/imperva-customers-protected-against-cve-2026-45247-in-mira…media-coverage
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45247government-resource

    Linked advisories

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    Badge preview for CVE-2026-45247
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-45247"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-45247.svg?lang=en" alt="CVE-2026-45247 – NEOSEC Intel" height="20"></a>