critical9.1
CVE-2026-33210
Ruby JSON has a format string injection vulnerability
Impact
### Impact A format string injection vulnerability than that 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 option isn't the default, if you didn't opt-in to use it, you are not impacted. ### Patches Patched in `2.19.2`. ### Workarounds The issue can be avoided by not using the `allow_duplicate_key: false` parsing option.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | json | >= 2.18.0, < 2.19.2 | 2.19.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Ruby-Lang | Json | from 2.14.0 before 2.15.2.1 from 2.16.0 before 2.17.1.2 from 2.18.0 before 2.19.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3
- https://access.redhat.com/errata/RHSA-2026:20596
- https://access.redhat.com/errata/RHSA-2026:20606
- https://access.redhat.com/errata/RHSA-2026:57565
- https://access.redhat.com/security/cve/CVE-2026-33210
- https://bugzilla.redhat.com/show_bug.cgi?id=2449871
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210.json
- https://github.com/advisories/GHSA-3m6g-2423-7cp3
- https://nvd.nist.gov/vuln/detail/CVE-2026-33210
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/json/CVE-2026-33210.yml