CVE-2017-6181
The parse_char_class function in regparse.c in the Onigmo (aka Oniguruma-mod) regular expression library, as used in Ruby 2.4.0, allows remote attackers to cause a denial of service (deep recursion and application crash) via a crafted regular expression.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The parse_char_class function in regparse.c in the Onigmo (aka Oniguruma-mod) regular expression library, as used in Ruby 2.4.0, allows remote attackers to cause a denial of service (deep recursion and application crash) via a crafted regular expression.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 3.65% probability · 90th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- ruby-lang/ruby
- Source
- cve@mitre.org
EPSS 3.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/97304Third Party Advisory, VDB Entry
- https://bugs.ruby-lang.org/issues/13234Issue Tracking, Vendor Advisory
- https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/57660Issue Tracking, Vendor Advisory
- http://www.securityfocus.com/bid/97304Third Party Advisory, VDB Entry
- https://bugs.ruby-lang.org/issues/13234Issue Tracking, Vendor Advisory
- https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/57660Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.