diff --git a/doc/POST_UPGRADE.md b/doc/POST_UPGRADE.md
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+[Borg pre-version 1.2.5 had CVE in archive format](https://github.com/borgbackup/borg/blob/1.2.8/docs/changes.rst#pre-125-archives-spoofing-vulnerability-cve-2023-36811). One liner to check if you're affected is:
+
+```sh
+sudo env BORG_RSH="ssh -i /root/.ssh/id___APP___ed25519 -oStrictHostKeyChecking=yes " BORG_PASSPHRASE="`yunohost app setting __APP__ passphrase`" BORG_RELOCATED_REPO_ACCESS_IS_OK=yes BORG_REPO="$(yunohost app setting __APP__ repository)" __INSTALL_DIR__/venv/bin/borg upgrade --show-rc --check-tam $BORG_REPOSITORY
+```
+
+Consult the linked documentation on how to interpert the result.