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Fencer Vulns
high 7.5

CVE-2016-9954 json

The backtrack compilation code in the Irregex package (aka IrRegular Expressions) before 0.9.6 for Scheme allows remote attackers to cause…

published 2017-04-21 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-10741

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

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.

Patch / fix

  • chicken Debian 14, Debian 13, Debian 12 4.12.0-0.2

debian advisories DEBIAN-CVE-2016-9954

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-9954 updated cvss 3.3

chicken: Excessive resource consumption due to irregex regular expression parsing

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.42% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-399 Resource Management Errors

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.