Security

Reporting Issues

If you believe that you’ve found a Syncthing-related security vulnerability, please report it by emailing security@syncthing.net. Do not report it in the open issue tracker. The security team PGP key can be used to send encrypted mail or to verify responses received from that address.

Release Signatures

The release PGP key can be used to verify the signatures on the official binary releases.

Verifying a Release Signature

Download the release (tar.gz file) and the checksum sha256sum.txt.asc file.

Example verifying release v1.23.6:

$ curl -sLO https://github.com/syncthing/syncthing/releases/download/v1.23.6/syncthing-linux-amd64-v1.23.6.tar.gz
$ curl -sLO https://github.com/syncthing/syncthing/releases/download/v1.23.6/sha256sum.txt.asc

Verify that the SHA256 checksum is correct for the release. Errors will be printed for the release files you did not download - these can be ignored. The important line is the one indicating the checksum is “OK” for the downloaded release file.

$ sha256sum -c sha256sum.txt.asc
...
sha256sum: syncthing-linux-386-v1.23.6.tar.gz: No such file or directory
syncthing-linux-386-v1.23.6.tar.gz: FAILED open or read
syncthing-linux-amd64-v1.23.6.tar.gz: OK  <-- this one
sha256sum: syncthing-linux-armv5-v1.23.6.tar.gz: No such file or directory
syncthing-linux-armv5-v1.23.6.tar.gz: FAILED open or read
...
sha256sum: WARNING: 14 lines are improperly formatted
sha256sum: WARNING: 35 listed files could not be read

Import the old and new release keys (only necessary if you haven’t done this previously).

$ curl -s https://syncthing.net/release-key.txt | gpg --import

Verify the signature on the checksum file. The import line is the “good signature” one.

$ gpg --verify sha256sum.txt.asc
gpg: Signature made Mo 03 Jul 2023 10:09:30 UTC
gpg:                using RSA key D26E6ED000654A3E
gpg: Good signature from "Syncthing Release Management <release@syncthing.net>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.