CVE-2020-23691: YFCMF v2.3.1 has a Remote Command Execution (RCE) vulnerability in the index.php.

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2020-23691 is a critical-severity flaw (CVSS 9.8) affecting yfcmf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

YFCMF v2.3.1 has a Remote Command Execution (RCE) vulnerability in the index.php.

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	3.4% (top 11%)
CISA exploited list	No
Published	2021-05-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: yfcmf

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

Am I affected?

Timeline

2021-05-14 15:15 UTCPublished CVE record published
2026-06-17 03:04 UTCUpdated Record last modified

yfcmf yfcmf DOWNGRADE

Affected: 2.3.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.3.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.3.1 (Debian / Ubuntu)

apt-cache madison yfcmf sudo apt install yfcmf=<VERSION_BEFORE_2.3.1> sudo apt-mark hold yfcmf

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

dnf --showduplicates list yfcmf sudo dnf downgrade yfcmf-<VERSION_BEFORE_2.3.1> sudo dnf versionlock add yfcmf

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-2020-23691?

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

Is CVE-2020-23691 being exploited?

CVE-2020-23691 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-2020-23691 affect?

CVE-2020-23691 affects yfcmf. Severity is critical (CVSS 9.8). YFCMF v2.3.1 has a Remote Command Execution (RCE) vulnerability in the index.php.

How urgent is CVE-2020-23691?

Priority 67/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2020-23689 MEDIUM 4.8 DOWNGRADE In YFCMF v2.3.1, there is a stored XSS vulnerability in the comments section of the news page.
CVE-2018-16431 HIGH 8.8 DOWNGRADE admin/admin/adminsave.html in YFCMF v3.0 allows CSRF to add an administrator account.

References

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