# frohoff/ysoserial

A proof-of-concept tool for generating payloads that exploit unsafe Java object deserialization.

Repository: https://github.com/frohoff/ysoserial
Canonical: https://ross.abutalabs.com/products/ysoserial
Homepage: http://frohoff.github.io/appseccali-marshalling-pickles/
Language: Java
License: MIT
License Family: permissive
Topics: java, deserialization, gadget, exploit, javadeser, jvm, serialization, poc, vulnerability
Last push: 2025-12-04T04:07:31+00:00

## Health v2 (maintenance only)
Score: 48/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 55, release rhythm 8, longevity 100
- inputs: {"age_days": 4235, "days_push": 272, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 9033, forks 1859 (observed 2026-08-28T04:10:28.028819+00:00)

## What it is
ysoserial is a proof-of-concept command-line tool that generates serialized Java payloads exploiting unsafe object deserialization using gadget chains found in common Java libraries. It wraps a user-specified command in a chosen gadget chain and outputs the serialized object for use in authorized security testing and research.

## Use cases
- generate java deserialization exploit payloads
- test applications for unsafe deserialization vulnerabilities
- demonstrate java gadget chain attacks in security research
- verify deserialization defenses against known gadget chains
- learn about java deserialization vulnerabilities
- payload generation for penetration testing java apps

## When to choose
- you need to test or demonstrate Java unsafe deserialization vulnerabilities in authorized engagements
- you want a well-known reference tool with gadget chains for many common Java libraries
- you are researching or teaching deserialization attack techniques

## When to avoid
- you need a defensive scanning tool rather than payload generation
- your target is not a Java/JVM application
- you lack explicit authorization to test the target system

## Facets
- artifact type: cli-tool
- maturity: active
- function: security, penetration-testing, vulnerability-scanning, serialization, cli
- domain: security, penetration-testing, developer-tools
- platform: jvm, cli, cross-platform
- tags: java-deserialization, gadget-chains, exploit-payloads, poc-tool, security-research, jvm

## Member repositories
- frohoff/ysoserial (main) score 48

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:28.028819+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:24:05.876440+00:00, confidence not recorded.
  - readme: https://github.com/frohoff/ysoserial (fetched 2026-08-28T04:10:28.028819+00:00, sha e07ae13517ed)
  - homepage: http://frohoff.github.io/appseccali-marshalling-pickles/ (fetched 2026-08-29T08:24:07.913904+00:00, sha bca2fbab715f)
- Data as of 2026-08-30T08:39:29.467469+00:00.