Vulnerability · Published Aug 30, 2026 · Assigned by EEF
CVE-2026-77831Algorithmic-complexity denial of service in AshPaperTrail full-diff list tracking
Low 2.1
In plain English
A low-severity security flaw in ash_paper_trail from ash-project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ash-project | ash_paper_trail | 0.1.1 – before 0.7.0 |
| ash-project | ash_paper_trail | 449cd2a93416853066378fa61c715e89f80dc854 – before e781f5d8840b07d57db99f9a4728298837d7b3a8 |
Weakness: CWE-407 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/ash-project/ash_paper_trail/security/advisories/GHSA-7c66-59m8-723c vendor-advisory, related
- https://cna.erlef.org/cves/CVE-2026-77831.html related
- https://osv.dev/vulnerability/EEF-CVE-2026-77831 related
- https://github.com/ash-project/ash_paper_trail/commit/e781f5d8840b07d57db99f9a4728298837d7b3a8 patch