[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f6-Scp6ZMCsnHd_VTpQAnv0WzVSmFHfF3d5C3Y88jyfI":3},{"article":4,"iocs":46,"watch_terms":47,"solutions":48,"lesson":137},{"id":5,"title":6,"slug":7,"summary":8,"ai_summary":9,"brief":10,"url":11,"image_url":12,"published_at":13,"ingested_at":14,"relevance_score":15,"entities":16,"category_id":28,"category":29,"article_tags":33},"68b89181-b32e-49ca-bb66-a212c67b6bbb","Fake Email Thread Tricks AI Summarizer Without Hidden Text","fake-email-thread-tricks-ai-summarizer-without-hidden-text-8110b3","Forcepoint X-Labs has published new research showing that indirect prompt injection against AI email summarizers can work without…","Forcepoint X-Labs research demonstrates that AI email summarizers can be manipulated through indirect prompt injection, even without hidden text or explicit commands. By inserting forged content into an email thread, attackers can alter the AI-generated summary to reflect fabricated details, such as incorrect dates and invoice amounts. This bypasses traditional detection methods that rely on hidden text or instruction-like phrasing, highlighting a new vulnerability in AI-powered summarization tools.","AI email summarizers can be tricked by forged email threads without hidden text.","https:\u002F\u002Fhackread.com\u002Ffake-email-thread-tricks-ai-summarizer-hidden-text\u002F","https:\u002F\u002Fhackread.com\u002Fwp-content\u002Fuploads\u002F2026\u002F09\u002Ffake-email-thread-tricks-ai-summarizer-hidden-text.jpg","2026-09-28T15:11:54+00:00","2026-09-28T18:00:35.298452+00:00",7,[17,20,23,26],{"name":18,"type":19},"Claude Haiku 4.5","product",{"name":21,"type":22},"Forcepoint","vendor",{"name":24,"type":25},"AI email summarizers","technology",{"name":27,"type":19},"Outlook","839da5c1-3c34-47e2-9499-f7201640e3ac",{"id":28,"icon":30,"name":31,"slug":32},null,"AI Security","ai-security",[34,39,41],{"category":35},{"id":36,"icon":30,"name":37,"slug":38},"80544778-fabb-4dcd-aa35-17492e5dcf4f","Vulnerabilities","vulnerabilities",{"category":40},{"id":28,"icon":30,"name":31,"slug":32},{"category":42},{"id":43,"icon":30,"name":44,"slug":45},"e7b231c8-5f79-4465-8d38-1ef13aea5a14","Threat Intelligence","threat-intelligence",[],[21,18],{"controls":49,"vendors":131},[50,75,104],{"slug":32,"name":51,"problem":52,"products":53},"AI application security","Prompt injection, data leaks through AI tools and unapproved AI use get caught.",[54,62,70],{"vendor_slug":55,"vendor_name":56,"vendor_logo":57,"product_slug":58,"product_name":59,"url":60,"description":61},"hiddenlayer","HiddenLayer","\u002Fvendor-logos\u002Fhiddenlayer.png","hiddenlayer-ai-security","HiddenLayer AI Security Platform","https:\u002F\u002Fhiddenlayer.com\u002F","Model scanning, AI red teaming and runtime protection for AI applications.",{"vendor_slug":63,"vendor_name":64,"vendor_logo":65,"product_slug":66,"product_name":67,"url":68,"description":69},"boomi","Boomi","\u002Fvendor-logos\u002Fboomi.png","boomi-agentstudio","Boomi Agentstudio","https:\u002F\u002Fboomi.com\u002Fplatform\u002Fagentstudio\u002F","Agent builder whose Agent Control Tower registers and monitors Boomi agents and agents on Amazon Bedrock, Microsoft Copilot and other platforms, keeps audit logs and can switch agents off where the provider allows it.",{"vendor_slug":63,"vendor_name":64,"vendor_logo":65,"product_slug":71,"product_name":72,"url":73,"description":74},"boomi-ai-gateway","Boomi AI Gateway","https:\u002F\u002Fboomi.com\u002Fplatform\u002Fai-gateway\u002F","Gateway for AI model and MCP tool traffic, built on Lunar.dev technology. It limits which tools each agent can call. Its enterprise version adds an approval step for new MCP servers and logs each call with the user or agent behind it.",{"slug":76,"name":77,"problem":78,"products":79},"email-security","Email security","Phishing, malware and invoice fraud are filtered out before they reach inboxes.",[80,88,96],{"vendor_slug":81,"vendor_name":82,"vendor_logo":83,"product_slug":84,"product_name":85,"url":86,"description":87},"check-point","Check Point","\u002Fvendor-logos\u002Fcheck-point.png","harmony-email","Harmony Email & Collaboration","https:\u002F\u002Fwww.checkpoint.com\u002Fharmony\u002Femail-security\u002F","Email and collaboration security for Microsoft 365 and Google Workspace.",{"vendor_slug":89,"vendor_name":90,"vendor_logo":91,"product_slug":92,"product_name":93,"url":94,"description":95},"abnormal","Abnormal AI","\u002Fvendor-logos\u002Fabnormal.png","abnormal-email-security","Abnormal Inbound Email Security","https:\u002F\u002Fabnormal.ai\u002F","API-based email security for Microsoft 365 and Google Workspace using behavioural models.",{"vendor_slug":97,"vendor_name":98,"vendor_logo":99,"product_slug":100,"product_name":101,"url":102,"description":103},"darktrace","Darktrace","\u002Fvendor-logos\u002Fdarktrace.png","darktrace-email","Darktrace \u002F EMAIL","https:\u002F\u002Fwww.darktrace.com\u002Fproducts\u002Femail","Email security that flags messages deviating from normal communication patterns.",{"slug":105,"name":106,"problem":107,"products":108},"security-awareness-training","Security awareness training and phishing simulation","People recognise and report attacks instead of falling for them.",[109,116,123],{"vendor_slug":110,"vendor_name":111,"vendor_logo":112,"product_slug":110,"product_name":113,"url":114,"description":115},"sosafe","SoSafe","\u002Fvendor-logos\u002Fsosafe.png","SoSafe Awareness Platform","https:\u002F\u002Fsosafe-awareness.com\u002F","Behaviour-based awareness training and phishing simulation in many languages.",{"vendor_slug":117,"vendor_name":118,"vendor_logo":119,"product_slug":105,"product_name":120,"url":121,"description":122},"knowbe4","KnowBe4","\u002Fvendor-logos\u002Fknowbe4.png","KnowBe4 Security Awareness Training","https:\u002F\u002Fwww.knowbe4.com\u002Fproducts\u002Fsecurity-awareness-training","Training library and simulated phishing with reporting.",{"vendor_slug":124,"vendor_name":125,"vendor_logo":126,"product_slug":127,"product_name":128,"url":129,"description":130},"huntress","Huntress","\u002Fvendor-logos\u002Fhuntress.png","managed-sat","Huntress Managed Security Awareness Training","https:\u002F\u002Fwww.huntress.com\u002Fplatform\u002Fsecurity-awareness-training","Security awareness training and phishing simulation, managed for you.",[132],{"slug":133,"name":21,"logo_path":134,"roles":135},"forcepoint","\u002Fvendor-logos\u002Fforcepoint.png",[136],"reported_by",{"slug":138,"title":139,"body":140,"framework_refs":141,"framework_notes":152},"ai-email-summarizers-vulnerable-to-indirect-prompt-injection-via-forged-thread-content","AI Email Summarizers Vulnerable to Indirect Prompt Injection via Forged Thread Content","Attackers can manipulate AI-powered email summarization tools by injecting forged content directly into email threads — no hidden text or explicit commands required. The root cause lies in AI models blindly trusting all content within a conversation context without validating source authenticity or detecting adversarial manipulation. This matters because users increasingly rely on AI-generated summaries to make financial and operational decisions, meaning a falsified invoice amount or meeting date could lead to real-world harm. Traditional detection mechanisms that scan for hidden text or instruction-like phrasing are entirely ineffective against this naturalistic injection technique, leaving a significant blind spot in enterprise AI deployments.",[142,143,144,145,146,147,148,149,150,151],"NIST AI RMF - GOVERN 1.1 (AI risk policies)","NIST AI RMF - MEASURE 2.5 (Adversarial testing)","NIST SP 800-53 SI-10 (Information Input Validation)","NIST SP 800-53 AU-2 (Audit Events \u002F Logging)","CIS Control 4 (Secure Configuration of Enterprise Assets)","CIS Control 8 (Audit Log Management)","CIS Control 14 (Security Awareness and Skills Training)","OWASP LLM Top 10 - LLM01 (Prompt Injection)","ISO\u002FIEC 42001 (AI Management System - Risk Management)","GDPR Article 22 (Automated Decision-Making Safeguards)",{}]