From $URL: An issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A stack out-of-bounds read occurs in match_at() during regular expression searching. A logical error involving order of validation and access in match_at() could result in an out-of-bounds read from a stack buffer. Upstream bug: https://github.com/kkos/oniguruma/issues/57 Upstream patch: https://github.com/kkos/oniguruma/commit/690313a061f7a4fa614ec5cc8368b4f2284e059b
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=28d415d0c3fc62cce6c5395c2c3a99199361a53a It seems that CVE-2017-9225 is not affected to version 5.9.x.
I am closing this as invalid: Ebuilds in repository were never affected.