CVE-2018-16278: phpkaiyuancms PhpOpenSourceCMS (POSCMS) V3.2.0 allows an unauthenticated user to execute arbitrary SQL command

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CRITICAL 9.8REMOTEDOWNGRADE

CVE-2018-16278 is a critical-severity flaw (CVSS 9.8) affecting phpopensourcecms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

phpkaiyuancms PhpOpenSourceCMS (POSCMS) V3.2.0 allows an unauthenticated user to execute arbitrary SQL commands via the diy/module/member/controllers/Api.php ajax_save_draft function with the dir parameter.

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 24%)
CISA exploited list	No
Weakness	CWE-89
Published	2018-08-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: phpkaiyuancms

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

Am I affected?

Timeline

2018-08-31 16:29 UTCPublished CVE record published
2026-06-17 01:44 UTCUpdated Record last modified

phpkaiyuancms phpopensourcecms DOWNGRADE

Affected: 3.2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.2.0 (Debian / Ubuntu)

apt-cache madison phpopensourcecms sudo apt install phpopensourcecms=<VERSION_BEFORE_3.2.0> sudo apt-mark hold phpopensourcecms

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

dnf --showduplicates list phpopensourcecms sudo dnf downgrade phpopensourcecms-<VERSION_BEFORE_3.2.0> sudo dnf versionlock add phpopensourcecms

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-2018-16278?

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

Is CVE-2018-16278 being exploited?

CVE-2018-16278 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-2018-16278 affect?

CVE-2018-16278 affects phpopensourcecms. Severity is critical (CVSS 9.8). phpkaiyuancms PhpOpenSourceCMS (POSCMS) V3.2.0 allows an unauthenticated user to execute arbitrary SQL commands via the diy/module/member/controllers/Api.php ajax_save_draft function with the dir parameter.

How urgent is CVE-2018-16278?

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

Software pages

PHP vulnerabilities

References

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