{"id":"CVE-2017-9225","details":"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 write in onigenc_unicode_get_case_fold_codes_by_str() occurs during regular expression compilation. Code point 0xFFFFFFFF is not properly handled in unicode_unfold_key(). A malformed regular expression could result in 4 bytes being written off the end of a stack buffer of expand_case_fold_string() during the call to onigenc_unicode_get_case_fold_codes_by_str(), a typical stack buffer overflow.","modified":"2026-05-17T11:54:03.085057722Z","published":"2017-05-24T15:29:00.230Z","database_specific":{},"references":[{"type":"FIX","url":"https://github.com/kkos/oniguruma/commit/166a6c3999bf06b4de0ab4ce6b088a468cc4029f"},{"type":"EVIDENCE","url":"https://github.com/kkos/oniguruma/issues/56"}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}