In LibSass 3.5.5, a heap-based buffer over-read exists in Sass::Prelexer::skip_over_scopes in prelexer.hpp when called from Sass::Parser::parse_import(), a similar issue to CVE-2018-11693.

An issue was discovered in LibSass through 3.5.4. An out-of-bounds read of a memory region was found in the function Sass::Prelexer::skip_over_scopes which could be leveraged by an attacker to disclose information or manipulated to read from unmapped memory causing a denial of service.