---
id: CVE-2026-77831
title: >-
  Inefficient Algorithmic Complexity vulnerability in ash-project
  ash_paper_trail allows a user who can submit a large array attribute to a
  paper-trailed create or update action to cause a denial of service through
  excessive CPU and memory…
summary: >-
  Inefficient Algorithmic Complexity vulnerability in ash-project
  ash_paper_trail allows a user who can submit a large array attribute to a
  paper-trailed create or update action to cause a denial of service through
  excessive CPU and memory…
severity: none
cwe:
  - CWE-407
published: '2026-08-30'
updated: '2026-08-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77831'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-77831.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash_paper_trail/commit/e781f5d8840b07d57db99f9a4728298837d7b3a8
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash_paper_trail/security/advisories/GHSA-7c66-59m8-723c
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-77831'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
epss: 0.0018
epssPercentile: 0.06685
ingestedAt: '2026-08-30T14:53:42.477Z'
---

## Overview

Inefficient Algorithmic Complexity vulnerability in ash-project ash_paper_trail allows a user who can submit a large array attribute to a paper-trailed create or update action to cause a denial of service through excessive CPU and memory use.

With full-diff change tracking, AshPaperTrail.ChangeBuilders.FullDiff.ListChange pairs each prior array element against the new list by rebuilding the remaining-elements accumulator with acc ++ [tuple] on every step, copying the growing list each time, so the pairing scales cubically in the array length. Nothing bounds the length and the value comes straight from action input, so one request carrying a large accepted {:array, _} attribute forces tens of seconds of CPU and multi-gigabyte allocations.

This issue affects ash_paper_trail: from 0.1.1 before 0.7.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.