🛡️ CVE-2026-33210 — json

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-134 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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 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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. Rated impact: confidentiality low, integrity none, availability high.

Weakness class

CVE-2026-33210 is classified as CWE-134: Externally Controlled Format String. User input is used as a format string, letting an attacker read or write memory through format specifiers.

Affected software

CVE-2026-33210 is recorded against 1 package.

  • json (from 2.14.0 up to 2.15.2.1)

Timeline and source

Published on 19 March 2026 and last revised on 21 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Package)
github.com (Web)

CVE-2026-33210 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector 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
CWE CWE-134
Public Exploit ✅ No
Source OSV
Published 2026-03-19
Updated 2026-08-12
Modified 2026-07-21
Fix URL N/A

Affected Packages

Software From version Fixed in
json 2.14.0 2.15.2.1

Similar Threats

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