Security briefing: October 2026

Attackers were definitely testing our cybersecurity best practices during Cybersecurity Awareness Month. A cloud region was knocked offline in Japan. Grocery stores across the US and Europe were either taken offline temporarily or lost produce. An AI agent chained two vulnerabilities to breach an organization that was established to help others with vulnerability disclosure. And finally, there were well over one thousand vulnerability patches in a single day. No seriously. Vulnerability management was like walking into a burning building in October. 

With that, let’s dive into this month’s security news.

Oct. 7: Ransomware takes down Japanese cloud infrastructure

• A Japanese SoftBank subsidiary called IDC Frontier confirmed a ransomware attack began on October 7, impacting nearly 500 companies and local governments. 
• Allegedly, customers saw messages claiming 3.6PB of data was encrypted in seven minutes. 
• The ransomware group claims to have deleted snapshots.
• This was in addition to other large-scale attacks across the country in October, including Burger King Japan, Nikkei, and Capcom.
• Shared responsibility includes your own backups. Test restoring them somewhere that isn’t your provider. 

Oct. 11: Hackers burn French fridges

• Overnight, between October 11 and 12, hackers forced refrigerators in hundreds of grocery stores across France into continuous defrost mode. 
• For six hours, the refrigeration equipment was pushed to temperatures of 50°C (122°F). 
• The Danish manufacturer, Danfoss, said the stores were running outdated firmware or had reached end-of-life support, which left equipment exposed to the internet. 
• This caused fires and potentially tens of millions of dollars in spoiled food. Although the incident was due to operational equipment exposure, it’s a global wake-up call to the physical impact of supply chain attacks. 

Oct. 20-21: Six Linux vulnerabilities dropped at once

• Trend Micro’s Zero Day Initiative (ZDI) sent five Linux kernel reports to the Linux kernel security team and one report to the ConnMan mailing list, all of which went out to the broader public mailing lists. 
• ZDI-CAN-33367 is a local privilege escalation in skb_zerocopy() with a public proof of concept. It’s another gap in the Dirty Frag fix (CVE-2026-43284) from May. 

Oct. 21: PHP2Shell

• PHP shipped two emergency releases on October 21 for CVE-2026-109618 and CVE-2026-109619. 
• An unauthenticated attacker can run code with HTTP requests alone, and researchers estimate 1.3 -1.9 million exposed hosts are potentially vulnerable. 
• Exploitation started before the patches existed. Amazon reported seeing an attempt on October 17. Organizations need to patch immediately, restart every PHP worker, and assume breach as they scan environments for signs of unauthorized access. 

Oct. 21: Node2Shell

• Node2Shell, also known as HTTP2Shell, landed on organizations’ radars after Node.js fixed an out-of-bounds write in its bundled Brotli decoder on October 21. 
• The first public GitHub repository tracking the CVE appeared only hours after the fix, and exploitation attempts were confirmed within days. 
• The decoder also ships in Bun, Python Brotli packages, and some Envoy configurations.

Additional Sysdig TRT findings

An AI agent chained two vulnerabilities to exploit a vulnerability disclosure program

• On October 2, Sysdig TRT published an initial blog on the breach of the Dutch Institute for Vulnerability Disclosure (DIVD) on September 21.
• The attacker exploited two vulnerabilities in the Zammad open source helpdesk tool. These were identified as CVE-2026-102489, a remote code execution flaw, and CVE-2026-102490, a local privilege escalation flaw. 
• Originally thought to be zero-days, Zammad said it received a report on CVE-2026-102489 in August, before the breach.

Pickle bypasses

• On October 27, the Sysdig TRT published an analysis on using pickles to bypass model-loading defenses in machine learning.
• Six documented CVE bypasses beat PyTorch weights_only, Keras safe_mode, and picklescan. The check and the loader disagreed about what the file was in each case.
• Loading a pickle file executes the code inside it. That’s a design flaw, not a patchable bug, so the fix is in the formatting. Switch to safetensors where possible and use runtime to detect what happens after the pickle is loaded.

Also in the news

• Microsoft patches a record 1,411 flaws: Vulnerability discovery is quickly outpacing security teams’ capability to remediate. KrebsOnSecurity said the prior month’s record of 972 patched flaws was 10 times a “normal” Microsoft patch load, and October dwarfed it. The increase is due to the internal use of AI platforms to find vulnerabilities within Microsoft products. Security teams need to prioritize reachability and exploitation. This month included one actively exploited zero-day (CVE-2026-96951), two publicly disclosed ones, and 70 critical flaws. 
• US and European grocery store operations disrupted: Ahold Delhaize confirmed a cybersecurity incident on October 12 after taking systems offline on October 11 to contain it. Albert Heijn, Etos, Gall & Gall, Delhaize, and Stop & Shop were some of the stores affected. 
• Nation-state threat actors using agentic AI: China-affiliated threat group Storm-0940 used agents to compromise ConnectWise customers, according to Microsoft on October 21. The group used the open source ARTEX framework to attempt sign-ins to more than 2,250 tenants. In multiple cases, the actors moved from targeting to privileged cloud access in less than three hours. 

Closing thoughts

Look at the clocks from this month. PHP2Shell was exploited four days before the patch. There was a PoC in a public repo for Node2Shell within hours. Storm-0940 went from targeting to privileged cloud access in under three hours. Patch what’s reasonable first, in a reasonable amount of time. But watch for what happens after an exploit is known. Attackers can’t hide behavior. 

And we just wrapped Cybersecurity Awareness Month. If you want to take a breather and step away from vulnerabilities for just a moment, here’s a list of simple things you should be doing daily to avoid a breach.

To stay informed between our monthly wrap-ups, you can get the latest from the Sysdig TRT on our blog, or follow my bi-weekly security newsletter musings on LinkedIn.

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