decrypted · 6 september 2026 · ransomware and cybercrime · vulnerabilities and patching · ai and llm security

A Magento zero-day is backdooring stores while Adobe still has no patch

A zero-day in Magento and Adobe Commerce is backdooring online stores right now, and there is no patch, no CVE and, as of this morning, no confirmed date for either. Dutch security firm Sansec, which caught the first attacks at 22:20 UTC on 4 September, has dubbed it StyleSmuggler. It works against every current version of the platform, including 2.4.9, and it has already compromised at least one store running 2.4.6-p15 with July and August's security updates fully applied. For the many UK retailers who still run Magento or Adobe Commerce behind their checkout, patch status is not what stands between them and this attack.

How it works

The flaw sits in Magento's GraphQL API, which most storefronts leave switched on whether or not they use it. An attacker sends a crafted request that manipulates a "styles" property, smuggling PHP code into a file Magento itself generates during normal operation, such as a failure report. Nothing runs yet: the code just sits there, planted. The second stage is the clever part. Magento's own automated "Payment Transaction Failed" email, the one that fires whenever a card gets declined, reads and executes that planted file as it builds the message. The store's own housekeeping does the attacker's work for it. No login, no password, no privileged account: just two ordinary-looking requests to features the store was already running.

Why "fully patched" didn't help

Sansec's own test stores prove the point: current builds, current patch levels, no exposure to any previously known bug, still fell. That is the definition of a zero-day, but it is worth dwelling on because so much of retail security is built around "are we patched." Here, being patched against every known CVE left a store just as open as one running years-old code, because the vulnerable behaviour was never a known bug to begin with. Adobe's next scheduled security release lands on 8 September; whether it covers this flaw is not yet confirmed.

The Secure by Design lesson

The design failure here is a feature left on by default that most stores never asked for. GraphQL ships enabled even on storefronts running a traditional theme rather than a headless or app frontend, so it sits exposed with no business justification. Secure by Design, in the NCSC's own language, means shipping products where the safe configuration is the default one, not an opt-in a store owner has to discover after the fact. For any UK organisation running Magento or Adobe Commerce, the immediate move is to disable GraphQL unless a headless frontend genuinely needs it, and to treat "we're on the latest patch" as necessary but no longer sufficient. Store owners should also watch for unexplained "kworker" processes or a burst of Payment Transaction Failed emails, both signs Sansec flags as compromise indicators.

Also this week

An AI gateway's own authentication fell over. CISA added CVE-2026-59822, an authentication bypass in the open-source LiteLLM proxy that many teams use to route requests to AI models and tools, to its Known Exploited Vulnerabilities catalogue this week. A forged bearer token could trick LiteLLM's MCP endpoint into swapping a failed key check for an empty, all-access session, letting an unauthenticated caller reach whatever tools and services sat behind the gateway. It is fixed in version 1.84.0. Any UK team that has wired an LLM up to internal tools through LiteLLM should treat this as the sharp end of what "least privilege for agents" is meant to prevent, not a footnote.

Qilin claims a Leicestershire packaging firm. The ransomware group has listed Complete Packaging Solutions, a UK fulfilment and packaging business registered in Leicestershire, on its leak site, threatening to publish stolen data. This is a claim on an extortion site, not a confirmed breach, and the company has not commented publicly; Decrypted treats it as such. It is a reminder that ransomware crews increasingly work down the supply chain to smaller UK firms that hold customer and stock data on behalf of bigger retail brands, well outside the security budgets those brands rely on.

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