In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.
https://support.f5.com/csp/article/K13322484?utm_source=f5support&%3Butm_medium=RSS
https://support.f5.com/csp/article/K13322484
https://security.netapp.com/advisory/ntap-20190806-0002/
https://lists.debian.org/debian-lts-announce/2023/09/msg00006.html
https://lists.debian.org/debian-lts-announce/2021/12/msg00013.html
https://lists.debian.org/debian-lts-announce/2019/07/msg00024.html
https://libssh2.org/changes.html
https://github.com/libssh2/libssh2/pull/350
https://github.com/libssh2/libssh2/compare/02ecf17...42d37aa
https://blog.semmle.com/libssh2-integer-overflow/
http://packetstormsecurity.com/files/172834/libssh2-1.8.2-Out-Of-Bounds-Read.html