My java application was installed on RHEL 8.5 OS Platform which has OpenSSL version 1.1.1. And the application was compiled on RHEL 5.6 OS platform where the OpenSSL version was 0.9.8. Also, the apache version in the application is 2.4.35. Previously the application is working smoothly with TLSv1.2 protocol in RHEL 8.5. But whenever I try to add the TLSv1.3 protocol, I can't able to start httpd services. I'm ending with the below error,

[01 May 2022 12:27:00:606] AH00526: Syntax error on line 60 of /xxxx/xxxxxx/xxxxxx/apache/ssl/ssl.conf:

[01 May 2022 12:27:00:640] SSLProtocol: Illegal protocol 'TLSv1.3'

Please find the below lines from "ssl.conf" file which I have modified like,

SSLProtocol -ALL +TLSv1.2 +TLSv1.3

Please let me know the possible ways to enable TLSv1.3 protocol with apache 2.4.35?


  • What is the result of command: openssl ciphers -v | awk '{print $2}' | sort | uniq? May 2 at 15:51
  • @RomeoNinov.. The result for the above command on RHEL 8.5 server was SSLv3, TLSv1, TLSv1.2, TLSv1.3 .. And the result on RHEL 5.6 server was SSLv2, SSLv3.
    – Learner
    May 4 at 6:20

1 Answer 1


You need to upgrade Apache to at least version 2.4.37 to use TLS 1.3 (see the changelog).


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