The Alias feature in SnakeYAML before 1.26 allows entity expansion during a load operation, a related issue to CVE-2003-1564.
CVE-2017-18640
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 2.8%, top 14% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 97.8%
- KEV
- Not listed
Published
December 12, 2019
Last Modified
November 21, 2024
References (118)
- cve@mitrehttps://bitbucket.org/asomov/snakeyaml/issues/377/allow-configuration-for-preventing-billion
- cve@mitrehttps://bitbucket.org/asomov/snakeyaml/wiki/Billion%20laughs%20attack
- cve@mitrehttps://bitbucket.org/snakeyaml/snakeyaml/issues/377
- cve@mitrehttps://bitbucket.org/snakeyaml/snakeyaml/wiki/Changes
- cve@mitrehttps://lists.apache.org/thread.html/r1058e7646988394de6a3fd0857ea9b1ee0de14d7bb28fee5ff782457%40%3Ccommits.atlas.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r154090b871cf96d985b90864442d84eb027c72c94bc3f0a5727ba2d1%40%3Ccommon-issues.hadoop.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r16ae4e529401b75a1f5aa462b272b31bf2a108236f882f06fddc14bc%40%3Ccommon-issues.hadoop.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r1703a402f30c8a2ee409f8c6f393e95a63f8c952cc9ee5bf9dd586dc%40%3Ccommits.cassandra.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r182e9cf6f3fb22b9be0cac4ff0685199741d2ab6e9a4e27a3693c224%40%3Ccommon-issues.hadoop.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r191ceadb1b883357384981848dfa5235cb02a90070c553afbaf9b3d9%40%3Ccommits.cassandra.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r1aab47b48a757c70e40fc0bcb1fcf1a3951afa6a17aee7cd66cf79f8%40%3Ccommon-commits.hadoop.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r1dfac8b6a7097bcb4979402bbb6e2f8c36d0d9001e3018717eb22b7e%40%3Cdev.atlas.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r1ffce2ed3017e9964f03ad2c539d69e49144fc8e9bf772d641612f98%40%3Ccommits.cassandra.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r20350031c60a77b45e0eded33e9b3e9cb0cbfc5e24e1c63bf264df12%40%3Ccommits.cassandra.apache.org%3E
- cve@mitrehttps://lists.apache.org/thread.html/r22ac2aa053b7d9c6b75a49db78125c9316499668d0f4a044f3402e2f%40%3Ccommon-issues.hadoop.apache.org%3E
Patch Availability(4)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | libyaml-snake-java-doc (1.12-2ubuntu0.16.04.1~esm2) @ xenial | 2026-05-27 | ubuntu |
| redhat | prometheus-jmx-exporter | 2021-08-19 | redhat |
| redhat | prometheus-jmx-exporter-0:0.12.0-6.el8 | 2020-11-04 | redhat |
| redhat | snakeyaml | 2020-06-17 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
Maven(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| org.yaml:snakeyaml | 1.10 ... 1.9 (22 versions) | 1.26 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(6)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
- Microsoft MSRCCVE-2017-186402025-10-02
The Alias feature in SnakeYAML before 1.26 allows entity expansion during a load operation, a related issue to CVE-2003-1564.
- Red HatRHSA-2020:2603MODERATE2019-12-12
RHSA-2020:2603 — Moderate
- Red HatRHSA-2020:4807MODERATE2019-12-12
RHSA-2020:4807 — Moderate
- Red HatRHSA-2021:3140MODERATE2019-12-12
RHSA-2021:3140 — Moderate
- Red HatRHSA-2021:3225MODERATE2019-12-12
RHSA-2021:3225 — Moderate
- UbuntuUSN-7368-1MEDIUM
SnakeYAML vulnerability
Data Freshness Timeline
(refreshed 6× in last 7d / 30× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-11 08:24 UTCEPSS rescore
- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-08 15:10 UTCEPSS rescore
- 2026-07-06 16:24 UTCEPSS rescore
- 2026-07-06 16:24 UTCEPSS rescore
- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-02 16:54 UTCEPSS rescore
- 2026-07-02 15:22 UTCOSV refresh
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-06-30 23:19 UTCEPSS rescore
- 2026-06-30 23:19 UTCEPSS rescore
- 2026-06-28 04:53 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-27 03:05 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-23 21:30 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
Show 34 moreShow fewer
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-14 23:14 UTCEPSS rescore
- 2026-06-14 13:13 UTCOSV refresh
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-10 22:15 UTCEPSS rescore
- 2026-06-10 13:19 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-07 15:22 UTCEPSS rescore
- 2026-06-07 15:22 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-27 10:39 UTCEG score recompute
- 2026-05-27 10:39 UTCVendor advisory
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-25 11:16 UTCOSV refresh
Frequently asked(5)
What is CVE-2017-18640?
When was CVE-2017-18640 disclosed?
Is CVE-2017-18640 actively exploited?
What is the CVSS score of CVE-2017-18640?
How do I remediate CVE-2017-18640?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2017-18640
Is Your Infrastructure Affected by CVE-2017-18640?
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