Match regex runs on over-length input in Ash.Type.String, enabling regex denial of service
## Summary Uncontrolled Resource Consumption vulnerability in ash-project ash allows an attacker to force an expensive regular expression to run on input that a length constraint should have already rejected. `Ash.Type.String.apply_constraints/2` (`lib/ash/type/string.ex`) evaluated the `:match` regex regardless of the `min_length` and `max_length` constraints on the same attribute. Because the length check did not gate the regex, an over-length value that the length constraint rejects still had the pattern applied to it, so the length limit that would otherwise bound the work never constrained the regex input. Against a backtracking pattern this yields catastrophic regex evaluation on attacker-sized input, and even a linear pattern runs on arbitrarily large input, consuming CPU per request. The fix skips the `:match` regex whenever a length constraint is violated, making the two checks order-independent. This issue affects ash: from 0.10.0 before 3.32.2.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-82735US | — | — | ||
Uncontrolled Resource Consumption vulnerability in ash-project ash allows an attacker to force an expensive regular expression to run on input that a length constraint should have… | ||||
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