CVE-2018-18835: upload_template() in system/changeskin.php in DocCms 2016.5.12 allows remote attackers to execute arbitrary PH

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2018-18835 is a critical-severity flaw (CVSS 9.8) affecting doccms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

upload_template() in system/changeskin.php in DocCms 2016.5.12 allows remote attackers to execute arbitrary PHP code via a template file.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.6% (top 25%)
CISA exploited list	No
Weakness	CWE-94
Published	2018-10-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: doccms

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-10-30 06:29 UTCPublished CVE record published
2026-06-17 01:47 UTCUpdated Record last modified

doccms doccms DOWNGRADE

Affected: 2016.5.12

Fixed in: no fixed release known

Safe to downgrade to: a release before 2016.5.12

1. Check installed version

apt-cache policy doccms || rpm -q doccms || doccms --version

2. No fixed release: DOWNGRADE to a release before 2016.5.12 (Debian / Ubuntu)

apt-cache madison doccms sudo apt install doccms=<VERSION_BEFORE_2016.5.12> sudo apt-mark hold doccms

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list doccms sudo dnf downgrade doccms-<VERSION_BEFORE_2016.5.12> sudo dnf versionlock add doccms

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-18835?

doccms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-18835 being exploited?

CVE-2018-18835 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-18835 affect?

CVE-2018-18835 affects doccms. Severity is critical (CVSS 9.8). upload_template() in system/changeskin.php in DocCms 2016.5.12 allows remote attackers to execute arbitrary PHP code via a template file.

How urgent is CVE-2018-18835?

Priority 63/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

References

← Back to latest CVEs