CVE-2026-82579: AshAi tool loop never terminates when all tool calls are filtered out, enabling denial of service

Severity: medium (CVSS 6.0 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-31 · updated 2026-09-01
Weakness: CWE-835

Description

Loop with Unreachable Exit Condition (Infinite Loop) vulnerability in ash-project ash_ai allows an attacker who can influence a model's output to hang the tool loop and drive unbounded, repeated model requests. AshAi.ToolLoop classifies a model response of :tool_calls, then filters the calls through normalize_tool_calls/2 and unprocessed_tool_calls/2. Both can empty the list: a call missing a valid name, or one reusing a tool_call_id that already has a result in history, is dropped. With an empty list the loop appended nothing and recursed with a byte-identical message list, so the conversation never advanced and the same request was re-sent every iteration. Under the supported max_iterations: :infinity this never terminated; otherwise it exhausted the full budget. Prompt-injected content can make the model re-emit a spent tool_call_id. The fix treats an empty post-filter list as terminal. This issue affects ash_ai: from 0.6.0 before 1.0.0.

Affected products

ash-project ash_ai: from 0.6.0 before 1.0.0 — fixed in 1.0.0

How to fix

Upgrade to a fixed version: ash-project ash_ai 1.0.0. Check the vendor advisory for mitigations.

References

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