Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M
CVE-2026-33210Ruby JSON has a format string injection vulnerability
Critical 9.1
In plain English
A critical-severity security flaw in json from ruby. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 60% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.9%top 40.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false parsing option is used to parse user supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:9 | ruby | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | ruby-bundled-gems | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | ruby-default-gems | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | ruby-devel | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | ruby-doc | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | ruby-libs | 4.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:10 | ruby4.0 | 4.0.3-34.el10_2 | ALSA-2026:20606 |
| AlmaLinux:10 | ruby4.0-devel | 4.0.3-34.el10_2 | ALSA-2026:20606 |
| AlmaLinux:10 | ruby4.0-doc | 4.0.3-34.el10_2 | ALSA-2026:20606 |
| AlmaLinux:10 | ruby4.0-rubygem-mysql2 | 0.5.7-34.el10_2 | ALSA-2026:20606 |
| AlmaLinux:10 | ruby4.0-rubygem-pg | 1.6.3-34.el10_2 | ALSA-2026:20606 |
| AlmaLinux:9 | rubygem-bigdecimal | 4.0.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-bundler | 4.0.6-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-io-console | 0.8.2-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-irb | 1.16.0-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-json | 2.18.0-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-minitest | 6.0.0-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-mysql2 | 0.5.7-1.module_el9.8.0+232+50f6dd36 | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-mysql2-doc | 0.5.7-1.module_el9.8.0+232+50f6dd36 | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-pg | 1.6.3-1.module_el9.8.0+232+50f6dd36 | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-pg-doc | 1.6.3-1.module_el9.8.0+232+50f6dd36 | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-power_assert | 3.0.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-psych | 5.3.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-racc | 1.8.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-rake | 13.3.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-rbs | 3.10.0-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-rdoc | 7.0.3-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-rexml | 3.4.4-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-rss | 0.3.2-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-test-unit | 3.7.5-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygem-typeprof | 0.31.1-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygems | 4.0.6-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| AlmaLinux:9 | rubygems-devel | 4.0.6-32.module_el9.8.0+251+5fdbd96b | ALSA-2026:20596 |
| Debian:14 | ruby-json | 2.19.2+dfsg-1 | DEBIAN-CVE-2026-33210 |
| Rocky Linux:10 | ruby4.0 | 0:4.0.3-34.el10_2 | RLSA-2026:20606 |
| Rocky Linux:9 | rubygem-mysql2 | 0:0.5.7-1.module+el9.8.0+40094+ce01217c | RLSA-2026:20596 |
| Rocky Linux:9 | rubygem-pg | 0:1.6.3-1.module+el9.8.0+40094+ce01217c | RLSA-2026:20596 |
| RubyGems | json | 2.19.2 | GHSA-3m6g-2423-7cp3 |
| RubyGems | json | 2.15.2.1 | GHSA-3m6g-2423-7cp3 |
| RubyGems | json | 2.17.1.2 | GHSA-3m6g-2423-7cp3 |
| Ubuntu:22.04:LTS | ruby-json | no fix listed | UBUNTU-CVE-2026-33210 |
| Ubuntu:24.04:LTS | ruby-json | no fix listed | UBUNTU-CVE-2026-33210 |
| Ubuntu:25.10 | ruby-json | no fix listed | UBUNTU-CVE-2026-33210 |
| Ubuntu:26.04:LTS | ruby-json | no fix listed | UBUNTU-CVE-2026-33210 |
| Ubuntu:26.10 | ruby-json | no fix listed | UBUNTU-CVE-2026-33210 |
Affected products (as reported)
Weakness: CWE-134 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
References
- https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3 x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-33210 vdb-entry, x_refsource_REDHAT
- RHBZ#2449871 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:20606 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20596 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:57565 vendor-advisory, x_refsource_REDHAT