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CVE

CVE-2026-33210

Ruby JSON has a format string injection vulnerability
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CVE

CVE-2026-33210

Ruby JSON has a format string injection vulnerability

Impact

A format string injection vulnerability than that lead to denial of service attacks or information disclosure, when the allowduplicatekey: 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 allowduplicatekey: false parsing option.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
8.3
-
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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3, https://nvd.nist.gov/vuln/detail/CVE-2026-33210, https://github.com/ruby/json, https://github.com/rubysec/ruby-advisory-db/blob/master/gems/json/CVE-2026-33210.yml

Severity

9.1

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
9.1
EPSS Probability
0.0002%
EPSS Percentile
0.05411%
Introduced Version
2.18.0,2.16.0,2.14.0
Fix Available
2.19.2,2.17.1.2,2.15.2.1

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