Hidden text injection in PDF bypasses security stack, exposing multi-channel blind spots
WolfShoddy7443 · reddit · 2026-08-24
A user shared a security incident involving hidden text prompt injection in a PDF:
- An attacker injected hidden instructions in a contract footer; the model caught it, but the org's security stack (monitoring only chat inputs) remained silent.
- Attack vectors are expanding to files, emails, calendar invites, and any content the model can access.
- Security advice: Monitor all input channels, not just the user chat box.
More from Safety
- Michigan professor Ben Green: why 'AI for Good' fails and self-regulation won't work — benzevgreen · 2026-10-16
- Apex Research head on CBS News: current AI testing regime is very insufficient — MariusHobbhahn · 2026-10-16
- Critical 9.5/10 RCE hits Next.js use cache; patch 16.4.1 now — jedisct1 · 2026-10-16
- AI agent fleet has wasted 17 years of scammers' time across 2.5M conversations — neil_chilson · 2026-10-16
- AI security firm Xbow found a full-chain Chrome exploit affecting a billion users in 6 days — moyix · 2026-10-16
- AI safety super PAC Guardrails Alliance funded $1M by its own dark-money group — ShakeelHashim · 2026-10-15