Service crash via unbounded untyped JSON recursion
Published Mar 11, 2022 · Updated Aug 27, 2025
Uncontrolled recursion in FasterXML jackson-databind allows remote attackers to crash Java services via deeply nested untyped JSON. UntypedObjectDeserializer recursively maps each nested object or array without a depth limit, exhausting the JVM call stack instead of rejecting excessive nesting. Exploitation requires deserialization of attacker-controlled JSON into Object, Collection, or Map<String,Object>; typed POJOs are unaffected unless they contain untyped properties.
Summary
What happened
Uncontrolled recursion in FasterXML jackson-databind allows remote attackers to crash Java services via deeply nested untyped JSON. UntypedObjectDeserializer recursively maps each nested object or array without a depth limit, exhausting the JVM call stack instead of rejecting excessive nesting. Exploitation requires deserialization of attacker-controlled JSON into Object, Collection, or Map<String,Object>; typed POJOs are unaffected unless they contain untyped properties.
The record
- CVE
- CVE-2020-36518
- Published
- Mar 11, 2022
- Updated
- Aug 27, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2022CVE publishedPublication date reported by the CVE source.
- Aug 27, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- DeepNestingUntypedDeserTest nested JSON reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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