CVE-2026-33210 is a critical format string injection vulnerability affecting Ruby JSON versions 2.14.0 through 2.19.1, specifically when parsing user-supplied documents with the allow_duplicate_key: false option. Rated 9.1 CRITICAL, this vulnerability allows an unauthenticated attacker to achieve remote Denial of Service or Information Disclosure with low attack complexity and no user interaction. There is currently no evidence of active exploitation, and no public exploit code or significant community discussion has been identified.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 2.14.0, < 2.15.2.1CPE matchmatch criteria | cpe:2.3:a:ruby-lang:json:*:*:*:*:*:ruby:*:* | ||
>= 2.16.0, < 2.17.1.2CPE matchmatch criteria | cpe:2.3:a:ruby-lang:json:*:*:*:*:*:ruby:*:* | ||
>= 2.18.0, < 2.19.2CPE matchmatch criteria | cpe:2.3:a:ruby-lang:json:*:*:*:*:*:ruby:*:* |
CVSS version used by this source: 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Ruby JSON has a format string injection vulnerability
Mar 19, 2026Ruby JSON has a format string injection vulnerability
Mar 19, 2026Ruby JSON has a format string injection vulnerability
Mar 19, 2026