Skip to content
CVE PROGRAM SOURCE RECORD5.9 Medium

CVE-2026-82735

Match regex runs on over-length input in Ash.Type.String, enabling regex denial of service

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

ash-project ash

Default version status: unaffected

  • 0.10.0 to < 3.32.2affected
pkg:hex/ash

ash-project ash

Default version status: unaffected

  • 05848d5f4affe60fddd812222a18ada080c0813b to < 14928412a1a94a69c47df8e98920d3a2b09cdec4affected
pkg:github/ash-project/ash

References