What is CVE-2019-6340?

CVE-2019-6340 is a high-severity vulnerability in Drupal, classified under Deserialization of Untrusted Data. CVSS score: 8.1/10. Published 2019-02-21.

How severe is CVE-2019-6340?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2019-6340 known to be exploited?

Yes. CVE-2019-6340 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25), indicating it is being actively exploited. 87 public proof-of-concept repositories are indexed.

Deserialization in Drupal

CVE-2019-6340

Some field types do not properly sanitize data from non-form sources in Drupal 8.5.x before 8.5.11 and Drupal 8.6.x before 8.6.10. This can lead to arbitrary PHP code execution in some cases. A site is only affected by this if one of the following conditions is met: The site has the Drupal 8 core RESTful Web Services (rest) module enabled and allows PATCH or POST requests, or the site has another web services module enabled, like JSON:API in Drupal 8, or Services or RESTful Web Services in Drupal 7. (Note: The Drupal 7 Services module itself does not require an update at this time, but you should apply other contributed updates associated with this advisory if Services is in use.)

Vulnerability class: Insecure Deserialization

Published 2019-02-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.920 (99.8th percentile), scored 2026-10-19.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.920 · newest: 0.920 · change: 0.000

Affected products

Drupal
Drupal Core — versions 8.5, 8.6

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-03-25. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-04-15.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

www.synology.com/security/advisory/Synology_SA_19_09 (Third Party Advisory)
www.exploit-db.com/exploits/46452/ (Patch, VDB Entry, Third Party Advisory, exploit)
www.drupal.org/sa-core-2019-003 (Mitigation, Vendor Advisory)
www.exploit-db.com/exploits/46510/ (Exploit, Third Party Advisory, exploit)
www.securityfocus.com/bid/107106 (VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
www.exploit-db.com/exploits/46459/ (Exploit, VDB Entry, Third Party Advisory, exploit)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2019-6340?: CVE-2019-6340 is a high-severity vulnerability in Drupal, classified under Deserialization of Untrusted Data. CVSS score: 8.1/10. Published 2019-02-21.
How severe is CVE-2019-6340?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2019-6340 known to be exploited?: Yes. CVE-2019-6340 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25), indicating it is being actively exploited. 87 public proof-of-concept repositories are indexed.