CVE-2016-9954
The backtrack compilation code in the Irregex package (aka IrRegular Expressions) before 0.9.6 for Scheme allows remote attackers to cause a denial of service (memory consumption) via a crafted regular expression with a repeating pattern.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The backtrack compilation code in the Irregex package (aka IrRegular Expressions) before 0.9.6 for Scheme allows remote attackers to cause a denial of service (memory consumption) via a crafted regular expression with a repeating pattern.
- 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
- 2.42% probability · 84th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-399
- Affected
- irregex project/irregex
- Source
- security@debian.org
EPSS 2.4% 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.openwall.com/lists/oss-security/2016/12/15/8Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/94942Third Party Advisory, VDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1413990Issue Tracking, Third Party Advisory, VDB Entry
- https://github.com/ashinn/irregex/commit/a16ffc86eca15fca9e40607d41de3cea9cf868f1Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/12/15/8Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/94942Third Party Advisory, VDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1413990Issue Tracking, Third Party Advisory, VDB Entry
- https://github.com/ashinn/irregex/commit/a16ffc86eca15fca9e40607d41de3cea9cf868f1Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.