Dropbear

Spec sheet

Purpose

Dropbear is a relatively small SSH server and client.Read 5 Oct 2026 · matt.ucc.asn.au

Platforms

The maker lists Linux, Mac OS X, FreeBSD, NetBSD, OpenBSD, Solaris, IRIX, Tru64, AIX, HPUX, and Cygwin among supported or tested platforms.Read 5 Oct 2026 · matt.ucc.asn.au

Support

The maker offers a low-volume mailing list for release notifications and general discussion.Read 5 Oct 2026 · matt.ucc.asn.au

License

Dropbear is open-source software distributed under an MIT-style license.Read 4 Oct 2026 · matt.ucc.asn.au

Algorithm defaults

The changelog says SHA-1 algorithms are disabled by default and post-quantum key exchange was added in release 2025.87.Read 4 Oct 2026 · matt.ucc.asn.au

Build options

Features can be disabled when compiling to save space, and the server, client, key generator, and key converter can be compiled into one binary.Read 5 Oct 2026 · matt.ucc.asn.au

Footprint

With uClibc on x86 and minimal options selected, Dropbear can compile to a 110 kB statically linked binary.Read 4 Oct 2026 · matt.ucc.asn.au

Forwarding

The server implements X11 forwarding and authentication-agent forwarding for OpenSSH clients.Read 5 Oct 2026 · matt.ucc.asn.au

Intended use

The maker says Dropbear is particularly useful for embedded Linux or other Unix systems, such as wireless routers.Read 5 Oct 2026 · matt.ucc.asn.au

Maker location

The Dropbear website says it is hosted by The University Computer Club in Perth, Australia.Read 5 Oct 2026 · matt.ucc.asn.au

Memory footprint

With uClibc on x86 and only minimal options selected, Dropbear can compile to a 110kB statically linked binary.Read 5 Oct 2026 · matt.ucc.asn.au

Multi-hop

Its multi-hop mode uses SSH TCP forwarding to tunnel through multiple SSH hosts in a single command.Read 5 Oct 2026 · matt.ucc.asn.au

Operation

Dropbear can run from inetd or as a standalone service.Read 4 Oct 2026 · matt.ucc.asn.au

Public key authentication

Dropbear is compatible with OpenSSH ~/.ssh/authorized_keys public key authentication.Read 5 Oct 2026 · matt.ucc.asn.au

Release

The official site lists version 2026.94, dated 23 July 2026, as the latest release.Read 4 Oct 2026 · matt.ucc.asn.au

Run modes

Dropbear can run from inetd or standalone.Read 5 Oct 2026 · matt.ucc.asn.au

Security update

The changelog says release 2026.93 fixed a use-after-free in X11 forwarding that could cause memory corruption for authenticated users when forwarding was enabled; X11 forwarding is not built by default.Read 5 Oct 2026 · matt.ucc.asn.au

Security updates

The changelog records a 2026.93 fix for a possible memory-corruption issue in X11 forwarding affecting authenticated users when that feature is enabled; X11 forwarding is not built by default.Read 4 Oct 2026 · matt.ucc.asn.au

Plans and prices

Every Dropbear plan and price →

Where Specifiction places it

• SSH Server Software#9 of 348.3