CVE-2026-82735

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

MEDIUM
5.9
CVSS Score
Published: September 1, 2026 at 03:19 AM UTC
Updated: September 1, 2026 at 09:31 PM UTC
1 product affected across 1 vendorAsh

Using ash by ash-project?

Get instant alerts when new vulnerabilities affect ash - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.9
Exploit prediction
EPSS 0.2%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

90%
0.10.0 ≤ v < 3.32.20.10.05848d5f4affe60fddd812222a18ada80c813b
Vendor states this is fixed in 14928412a1a94a69c47df8e98920d3a2b09cdec4 (fixed)
Affected range stops below 3.32.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-400

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card