CVE-2017-18640

HIGH

SnakeYAML < 1.26 - XML Entity Expansion via Alias Feature

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2017-18640. PoCs published by dawetmaster, andikahilmy.

AI-analyzed exploit summary This repository contains a vulnerable version of SnakeYAML (1.17-SNAPSHOT) with Dockerfiles to test CVE-2017-18640, a deserialization vulnerability. The included source code and build configuration allow for exploitation testing across Java 6, 7, and 8 environments.

Description

The Alias feature in SnakeYAML before 1.26 allows entity expansion during a load operation, a related issue to CVE-2003-1564.

Exploits (2)

nomisec WORKING POC
by dawetmaster · poc
https://github.com/dawetmaster/CVE-2017-18640-snakeyaml-vulnerable

This repository contains a vulnerable version of SnakeYAML (1.17-SNAPSHOT) with Dockerfiles to test CVE-2017-18640, a deserialization vulnerability. The included source code and build configuration allow for exploitation testing across Java 6, 7, and 8 environments.

Classification
Working Poc 90%
Attack Type
Deserialization
Complexity
Moderate
Reliability
Reliable
Target: SnakeYAML 1.17-SNAPSHOT
No auth needed
Prerequisites: Docker · Java environment (6, 7, or 8)
devstral-2 · analyzed Mar 14, 2026 Full analysis →
nomisec WORKING POC
by andikahilmy · poc
https://github.com/andikahilmy/CVE-2017-18640-snakeyaml-vulnerable

This repository contains a vulnerable version of SnakeYAML (1.17-SNAPSHOT) with Dockerfiles to test the CVE-2017-18640 deserialization vulnerability. The included source code and build configuration allow for exploitation testing across Java 6, 7, and 8 environments.

Classification
Working Poc 90%
Attack Type
Deserialization
Complexity
Moderate
Reliability
Reliable
Target: SnakeYAML 1.17-SNAPSHOT
No auth needed
Prerequisites: Java environment (6, 7, or 8) · Docker for testing
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (59)

Core 59
Core References
Exploit, Issue Tracking, Third Party Advisory
https://bitbucket.org/snakeyaml/snakeyaml/issues/377
Release Notes, Third Party Advisory
https://bitbucket.org/snakeyaml/snakeyaml/wiki/Changes
Third Party Advisory vendor-advisory
https://security.gentoo.org/glsa/202305-28

Scores

CVSS v3 7.5
EPSS 0.0360
EPSS Percentile 88.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-776
Status published
Products (8)
fedoraproject/fedora 31
fedoraproject/fedora 32
oracle/peoplesoft_enterprise_pt_peopletools 8.56
oracle/peoplesoft_enterprise_pt_peopletools 8.57
oracle/peoplesoft_enterprise_pt_peopletools 8.58
org.yaml/snakeyaml 0 - 1.26Maven
quarkus/quarkus < 1.3.4
snakeyaml_project/snakeyaml < 1.26
Published Dec 12, 2019
Tracked Since Feb 18, 2026