There's now a patch available in the upstream git (see attachment).
https://github.com/cyrusimap/cyrus-imapd/commit/f4b4c5bf65c1737aeaccc64678f5d4c31a1de48f
Cheers,
Christian
>From f4b4c5bf65c1737aeaccc64678f5d4c31a1de48f Mon Sep 17 00:00:00 2001
From: ellie timoney <el...@fastmail.com>
Date: Fri, 15 May 2020 09:47:56 +1000
Subject: [PATCH] lmtp_err: fix invalid position parameter usage
This fails under FORTIFY_SOURCE (#1981), which I guess more and more
platforms are starting to use by default.
Fixes #3035
---
imap/lmtp_err.et | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/imap/lmtp_err.et b/imap/lmtp_err.et
index cd5c1ac64..4e2701303 100644
--- a/imap/lmtp_err.et
+++ b/imap/lmtp_err.et
@@ -45,7 +45,7 @@ error_table lmtp
# Enhanced Mail System Status Codes (RFC 3463)
ec LMTP_OK,
- "250 2.1.5 Ok SESSIONID=<%2$s>"
+ "250 2.1.5 %s SESSIONID=<%s>"
ec LMTP_MAILBOX_ERROR,
"451 4.2.0 %s"
