CVE-2020-9546
CRITICALCVE-2020-9546 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in com.fasterxml.jackson.core:jackson-databind. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2020-9546 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
jackson-databind mishandles the interaction between serialization gadgets and typing
Real-World Exposure
com.fasterxml.jackson.core:jackson-databindReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to org.apache.hadoop.shaded.com.zaxxer.hikari.HikariConfig (aka shaded hikari-config).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.fasterxml.jackson.core:jackson-databind | ≥ 2.9.0&&< 2.9.10.4 | 2.9.10.4 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.fasterxml.jackson.core:jackson-databind. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update com.fasterxml.jackson.core:jackson-databind to 2.9.10.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-9546 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2020-9546 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2020-9546. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat OpenStack Platform ships OpenDaylight, which contains the vulnerable jackson-databind. However, OpenDaylight does not expose jackson-databind in a way that would make it vulnerable, lowering the impact of the vulnerability for OpenDaylight. As such, Red Hat will not be providing a fix for OpenDaylight at this…
Frequently Asked Questions
Is CVE-2020-9546 in your dependencies?
O3 detects CVE-2020-9546 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.