Floci CVE-2026-108598

Exploitation requires a pre-2.2.0 Floci instance whose API Gateway service (or the equivalent AppSync resolver path) is network-reachable to the attacker, and whose VTL template processing runs on the pre-patch engine with no reflection sandbox. The concrete prerequisite is the ability to create/define a REST API with a MOCK integration carrying a Velocity mapping template that uses $util reflection to reach Runtime or ProcessBuilder - a capability the vulnerable engine exposes to unauthenticated callers per the CVSS PR:N vector. Limiting factors: the target must be running an affected version (1.1.0 up to but not including 2.2.0); after the 2.2.0 fix, templates render inside SecureUberspector which blocks Class, ClassLoader, Runtime, ProcessBuilder, System, Thread, and java.io.File, plus loop/output/time limits, neutralizing the reflection path. Because Floci is primarily a local/CI developer emulator, realistic exposure depends on whether its control plane is bound beyond localhost.

All exploitability signals align toward high real-world risk. The vendor-supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N) describes network-reachable, low-complexity, unauthenticated exploitation with high confidentiality, integrity, and availability impact (VC:H/VI:H/VA:H), scoring 9.3, and the description corroborates this - unauthenticated OS command execution in the Floci JVM via a crafted Velocity (VTL) mapping template. Publicly available exploit code exists (ghostx-86 PoC) and a vendor patch (2.2.0) is available, and the finding was reported by VulnCheck, a credible source. However, the input provides NO EPSS score and NO CISA KEV listing, so this is 'publicly available exploit code exists' - NOT confirmed active exploitation; do not treat it as in-the-wild. The dominant counterweight is deployment context: Floci is a niche open-source AWS-service emulator (typically a developer/CI tool) rather than ubiquitous production infrastructure, so despite the near-maximal CVSS, aggregate real-world exposure is constrained by how narrowly the product is deployed and whether its API Gateway/AppSync control plane is network-reachable. Net: a genuine high-severity RCE that should be patched promptly where Floci is exposed, but likely targeted/limited rather than mass-exploited given the product footprint.

An attacker with network access to a pre-2.2.0 Floci instance's API Gateway control plane creates a REST API with a MOCK integration whose VTL mapping template uses $util-based reflection to reach java.lang.Runtime or ProcessBuilder. Invoking the API renders the template and executes attacker-chosen OS commands inside the Floci JVM, with no authentication required. A public proof-of-concept for this exact API Gateway VTL RCE path is available.