Security Digest · Vulnerability record
CVE-2026-16723: fastjson has a remote code execution (RCE) vulnerability
A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83.
CVSS 9.0 Critical EPSS 0.7% · p51
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.7%, percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
com.alibaba:fastjson(Maven) >= 1.2.68, <= 1.2.83, no fixed version listed. Check your lockfile, including transitive dependencies.
What it is
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.
From the GitHub advisory
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.
Weakness type: CWE-20, CWE-502.
Product: com.alibaba:fastjson (Maven) · Assigned by: alibaba · Published: 2026-07-23
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Maven | com.alibaba:fastjson | >= 1.2.68, <= 1.2.83 | none listed |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Alibaba | Fastjson | 1.2.68 <= 1.2.83 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| alibaba | 3.1 | 9 Critical | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: high (needs special conditions)
- Privileges required: none (no login)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.66% probability of exploitation activity in the next 30 days; percentile 51.
Timeline
- — CVE record last updated
- — CVE record published by alibaba
- — GitHub-reviewed advisory GHSA-crf3-v9rr-v7hj published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- github.com github.com
Vulnerability records
- GitHub Advisory GHSA-crf3-v9rr-v7hj github.com
- CVE.org record CVE-2026-16723 cve.org
- NVD entry CVE-2026-16723 nvd.nist.gov