What is CVE-2018-20718?

CVE-2018-20718 is a critical-severity vulnerability in Pydio, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-01-15.

How severe is CVE-2018-20718?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2018-20718 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Deserialization in Pydio

CVE-2018-20718

In Pydio before 8.2.2, an attack is possible via PHP Object Injection because a user is allowed to use the $phpserial$a:0:{} syntax to store a preference. An attacker either needs a "public link" of a file, or access to any unprivileged user account for creation of such a link.

Vulnerability class: Insecure Deserialization

Published 2019-01-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.037 (89.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.037 · newest: 0.037 · change: 0.000

Affected products

Pydio

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

Public proof-of-concept exploits

References

blog.ripstech.com/2018/pydio-unauthenticated-remote-code-execution/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2018-20718?: CVE-2018-20718 is a critical-severity vulnerability in Pydio, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-01-15.
How severe is CVE-2018-20718?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-20718 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.