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Fencer Vulns
critical 9.8

CVE-2017-9225 in the critical feed json

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.

published 2017-05-24 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-18163

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.1%
EPSS 3.1% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

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.

Patch / fix

  • libonig Debian 14, Debian 13, Debian 12 6.1.3-2

debian advisories DEBIAN-CVE-2017-9225

  • oniguruma hummingbird 1 6.9.10-4.1.hum1

red hat advisories RHSA-2026:7545

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-2017-9225 updated cvss 5.9

oniguruma: Out-of-bounds stack write in onigenc_unicode_get_case_fold_codes_by_str() during regular expression compilation

  • Red Hat CloudForms Management Engine 5 ruby-200-ruby, rh-ruby22-ruby Red Hat Subscription Asset Manager ruby193-ruby
    under investigation
  • Red Hat Hardened Images oniguruma 6.9.10-4.1.hum1
    fixed: vendor fix RHSA-2026:7545
  • Red Hat Enterprise Linux 5 php, ruby, php53 Red Hat Enterprise Linux 6 php, ruby, php-gd, php-cli, php-dba, php-fpm, +27 more Red Hat Enterprise Linux 7 php, ruby, php-gd, php-cli, php-dba, php-fpm, +30 more Red Hat OpenShift Enterprise 2 php Red Hat Software Collections rh-php56-php, rh-php70-php, rh-ruby22-ruby, rh-ruby23-ruby, rh-ruby24-ruby, rh-php56-php-gd, +99 more
    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

3.08% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kkos/oniguruma/issues/56 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
Technology feeds

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.