v1.20.18

9001/copypartyv1.20.18Jul 9, 2026by 9001

AI Summary

Introduces volume shadowing and disables the bwrap sandbox for ffmpeg due to compatibility issues.

Key Highlights

Shadowing feature allows unmapping volumes via `//NULL`.
bwrap sandbox for ffmpeg is now default-disabled due to OS compatibility issues.
Logfiles now rotate (never overwrite) on startup unless configured otherwise.
Thumbnail expiration I/O optimization.

New Features

Shadowing support
Toggle for bwrap sandbox
Log rotation improvements

Full Release Notes

<img src="https://github.com/9001/copyparty/raw/hovudstraum/docs/logo.svg" width="250" align="right"/>

* read-only demo server at https://a.ocv.me/pub/demo/
* [docker image](https://github.com/9001/copyparty/tree/hovudstraum/scripts/docker) ╱ [similar software](https://github.com/9001/copyparty/blob/hovudstraum/docs/versus.md) ╱ [client testbed](https://cd.ocv.me/b/)

there is a [discord server](https://discord.gg/25J8CdTT6G) with an `@everyone` in case of future important updates, such as [vulnerabilities](https://github.com/9001/copyparty/security) (most recently 2026-07-06)

## recent important news

* [v1.20.17 (2026-07-06)](https://github.com/9001/copyparty/releases/tag/v1.20.17) fixed a vuln when a volume has both filekeys and dirkeys enabled
* [v1.20.17 (2026-07-06)](https://github.com/9001/copyparty/releases/tag/v1.20.17) introduced csp nonces, possibly breaking some javascript-based plugins

## 🧪 new features

* [shadowing](https://github.com/9001/copyparty/#shadowing): filesystem-path `//NULL` will fully unmap a volume from the server's filesystem (no more `/var/lib/empties/4` jank) 88846061

## 🩹 bugfixes

* fix a false-positive warning on startup 12878e6c1cbf4417da42d46230dff686dd48760b

## 🔧 other changes

* #1552 #1551 default-disabled the bwrap ffmpeg sandbox; 85a8cc99
  * sandboxing can fail in too many creative ways (funky linux distros with funky filesystem layouts and policies) so autoconfiguring bwrap is not feasible
  * to enable it, set `use-bwrap: y` after adjusting [th-bwrap](https://copyparty.eu/cli/#g-th-bwrap) to match your OS/env
    * see the default `th-bwrap` value in `--help` on your server for a best-effort guess
* always rotate (never overwrite) `-lo` logfiles on startup unless `--rlo no` 29e145f5
* thumbnails: save a tiny bit of I/O by not refreshing expiration-times if `th-clean` (expiration) is disabled anyways e15f2927

## 🌠 fun facts

* no

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## ⚠️ not the [latest version](https://github.com/9001/copyparty/releases/latest/)!