CVE-2021-23899

Name: CVE-2021-23899
Creator: NVD / NIST
Published: 2021-01-13T16:15:14.413+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.07%

Last modified Jun 17, 2026

CVE-2021-23899 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. OWASP json-sanitizer before 1.2.2 may emit closing SCRIPT tags and CDATA section delimiters for crafted input. This allows an attacker to inject arbitrary HTML or XML into embedding documents.. EPSS estimates a 2.07% chance of exploitation in the next 30 days.

Description

OWASP json-sanitizer before 1.2.2 may emit closing SCRIPT tags and CDATA section delimiters for crafted input. This allows an attacker to inject arbitrary HTML or XML into embedding documents.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.07%

79.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-611

Affected Software

Vendor	Product	Versions
Owasp	Json-Sanitizer	< 1.2.2

References

https://github.com/OWASP/json-sanitizer/commit/a37f594f7378a1c76b3283e0dab9e1ab1dc0247ePatch, Third Party Advisory
https://github.com/OWASP/json-sanitizer/compare/v1.2.1...v1.2.2Patch, Third Party Advisory
https://groups.google.com/g/json-sanitizer-support/c/dAW1AeNMoA0Third Party Advisory
https://github.com/OWASP/json-sanitizer/commit/a37f594f7378a1c76b3283e0dab9e1ab1dc0247ePatch, Third Party Advisory
https://github.com/OWASP/json-sanitizer/compare/v1.2.1...v1.2.2Patch, Third Party Advisory
https://groups.google.com/g/json-sanitizer-support/c/dAW1AeNMoA0Third Party Advisory

Timeline

Published: Jan 13, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-23899?

OWASP json-sanitizer before 1.2.2 may emit closing SCRIPT tags and CDATA section delimiters for crafted input. This allows an attacker to inject arbitrary HTML or XML into embedding documents.

How severe is CVE-2021-23899?

CVE-2021-23899 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.07% probability of exploitation in the next 30 days.

How do I fix CVE-2021-23899?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-23899?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST