CVE-2026-16723: CWE-20 Improper input validation in Alibaba Fastjson
A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.
AI Analysis
Technical Summary
This vulnerability in Alibaba Fastjson (versions 1.2.68 to 1.2.83) involves improper input validation (CWE-20) and deserialization issues (CWE-502) that allow remote code execution. Exploitation does not require enabling AutoType or additional classpath gadgets, making it exploitable under default settings. The CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) reflects network attack complexity with high impact on system confidentiality, integrity, and availability. The vendor has not provided an official fix or remediation level at this time.
Potential Impact
Successful exploitation allows an unauthenticated remote attacker to execute arbitrary code on affected systems running Fastjson versions 1.2.68 through 1.2.83. This compromises system confidentiality, integrity, and availability. The vulnerability is exploitable under default configurations without additional enabling of features, increasing risk exposure.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider restricting network exposure of affected Fastjson instances and applying additional input validation controls where possible.
CVE-2026-16723: CWE-20 Improper input validation in Alibaba Fastjson
Description
A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.
CVSS v3.1
Score 9.0critical
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Alibaba Fastjson (versions 1.2.68 to 1.2.83) involves improper input validation (CWE-20) and deserialization issues (CWE-502) that allow remote code execution. Exploitation does not require enabling AutoType or additional classpath gadgets, making it exploitable under default settings. The CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) reflects network attack complexity with high impact on system confidentiality, integrity, and availability. The vendor has not provided an official fix or remediation level at this time.
Potential Impact
Successful exploitation allows an unauthenticated remote attacker to execute arbitrary code on affected systems running Fastjson versions 1.2.68 through 1.2.83. This compromises system confidentiality, integrity, and availability. The vulnerability is exploitable under default configurations without additional enabling of features, increasing risk exposure.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider restricting network exposure of affected Fastjson instances and applying additional input validation controls where possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- alibaba
- Date Reserved
- 2026-07-23T02:40:02.606Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a61d2cf9c2644c7f8b6a262
Added to database: 07/23/2026, 08:37:35 UTC
Last enriched: 08/08/2026, 15:30:16 UTC
Last updated: 09/06/2026, 04:05:03 UTC
Views: 280
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