Hi @ved144kumar ,
In order to go from 1.x to 3.x you will first need to go to 2.x.
I tested this and got it working, I first setup 1.3.20, then upgraded to 2.19.2.
Then I backed up the security indices, deleted them and restored them. This will recreate the versions on 2.19.2. Which afterwards the upgrade will run successfully giving the version is no longer restricting.
You can backup and restore using the following with security admin -
Backup
"/usr/share/opensearch/plugins/opensearch-security/tools/securityadmin.sh" -backup "/usr/share/opensearch/config/opensearch-security" -icl -key "/usr/share/opensearch/config/kirk-key.pem" -cert "/usr/share/opensearch/config/kirk.pem" -cacert "/usr/share/opensearch/config/root-ca.pem" -nhnv
Restore
"/usr/share/opensearch/plugins/opensearch-security/tools/securityadmin.sh" -cd "/usr/share/opensearch/config/opensearch-security" -icl -key "/usr/share/opensearch/config/kirk-key.pem" -cert "/usr/share/opensearch/config/kirk.pem" -cacert "/usr/share/opensearch/config/root-ca.pem" -nhnv
Then after upgrading you can run the following to confirm versions of the new indices -
curl -XGET --cert ./kirk.pem --key ./kirk-key.pem --cacert ./root-ca.pem "https://localhost:9200/.opendistro_security/_settings?human"
{".opendistro_security":{"settings":{"index":{"replication":{"type":"DOCUMENT"},"creation_date_string":"2025-10-06T11:14:00.019Z","number_of_shards":"1","auto_expand_replicas":"0-all","provided_name":".opendistro_security","creation_date":"1759749240019","number_of_replicas":"1","uuid":"ZDKyfhKCTfaKuqIdhxfOtA","version":{"upgraded":"137237827","created_string":"2.19.2","upgraded_string":"3.2.0","created":"136408027"}}}}}
You can see the created_string is updated from backup, delete, and restore in 2.19.2, which was 1.3.20. Which enabled the upgrade to 3.2.0.
Leeroy.