What Happened
A critical security flaw impacting Rejetto HTTP File Server (HFS) is witnessing active exploitation attempts, according to VulnCheck. The vulnerability in question is CVE-2026-61500 (CVSS score: 9.3), a case of session forgery stemming from the use of a weak pseudo-random number generator (PRNG) that can lead to a predictable key, which an attacker can then use to gain unauthorized access and
Why It Matters
The report describes active exploitation of CVE-2026-61500 in Rejetto HFS 3.0.0–3.2.0: attackers can reconstruct a weak PRNG state, forge an administrator session cookie, and achieve remote code execution through the server_code feature. This is a conventional infrastructure vulnerability, not an AI-specific threat, so its direct relevance to RealGround is low. RealGround analysis: organizations using AI agents or AI-connected file services should assess whether compromised HFS systems could expose agent credentials, workflows, or business logic, and should test authorization boundaries and abuse paths.
RealGround Analysis
This signal maps to AI agent abuse. Organizations using AI agents, LLM APIs, SaaS integrations, or sensitive data workflows should review whether this class of issue could create unauthorized tool execution, data leakage, weak approval gates, or unmanaged supply-chain exposure.
Recommended Actions
- Restrict AI agent tool permissions and production write paths.
- Review sensitive data access across prompts, logs, embeddings, memory, and SaaS integrations.
- Add human approval workflows for high-impact or state-changing actions.
- Run prompt injection and indirect prompt injection tests against affected workflows.
- Document the owner, control gap, and remediation deadline for this risk class.
Source
https://thehackernews.com/2026/10/attackers-target-rejetto-hfs-flaw-that.html