CVE-2023-27397: Unrestricted upload of file with dangerous type exists in MicroEngine Mailform version 1.1.0 to 1.1.8

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2023-27397 is a critical-severity flaw (CVSS 9.8) affecting mailform. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Unrestricted upload of file with dangerous type exists in MicroEngine Mailform version 1.1.0 to 1.1.8. If the product's file upload function and server save option are enabled, a remote attacker may save an arbitrary file on the server and execute it.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-434
Published	2023-05-23
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: microengine

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

Am I affected?

Timeline

2023-05-23 02:15 UTCPublished CVE record published
2026-06-17 05:44 UTCUpdated Record last modified

microengine mailform UPGRADE

Affected: >= 1.1.0 and < 1.1.9

Fixed in: 1.1.9

Safe to downgrade to: a release before 1.1.0

1. Check installed version

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

2. UPGRADE to 1.1.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mailform

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mailform

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.1.0 (Debian / Ubuntu)

apt-cache madison mailform sudo apt install mailform=<VERSION_BEFORE_1.1.0> sudo apt-mark hold mailform

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mailform sudo dnf downgrade mailform-<VERSION_BEFORE_1.1.0> sudo dnf versionlock add mailform

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-2023-27397?

mailform: upgrade to 1.1.9. Exact commands for each OS are on this page.

Is CVE-2023-27397 being exploited?

CVE-2023-27397 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-2023-27397 affect?

CVE-2023-27397 affects mailform. Severity is critical (CVSS 9.8). Unrestricted upload of file with dangerous type exists in MicroEngine Mailform version 1.1.0 to 1.1.8. If the product's file upload function and server save option are enabled, a remote attacker may save an arbitrary file on the server and

How urgent is CVE-2023-27397?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2023-27507 CRITICAL 9.8 UPGRADE MicroEngine Mailform version 1.1.0 to 1.1.8 contains a path traversal vulnerability

References

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