Sympa 6.2.38 through 6.2.52 allows remote attackers to cause a denial of service (disk consumption from temporary files, and a flood of notifications to listmasters) via a series of requests with malformed parameters.
github.com/sympa-community/sympa/issues/886
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6TMVZ5LVYCCIHGEC7RQUMGUE7DJWUXN7/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A3FUYYLV6URRLAJVWXNJYK2CNOKKNHXC/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XO4WJYNNHWM7DUKCN4EWYYYPXZSOI7BQ/
sympa-community.github.io/security/2020-001.html
www.debian.org/security/2020/dsa-4818