CVE-2020-29597: IncomCMS 2.0 has a modules/uploader/showcase/script.php insecure file upload vulnerability

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CRITICAL 9.8REMOTEDOWNGRADE

CVE-2020-29597 is a critical-severity flaw (CVSS 9.8) affecting incomcms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IncomCMS 2.0 has a modules/uploader/showcase/script.php insecure file upload vulnerability. This vulnerability allows unauthenticated attackers to upload files into the server.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
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	71.3% (top 1%)
CISA exploited list	No
Weakness	CWE-434
Published	2020-12-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: incomcms project

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

Am I affected?

Timeline

2020-12-07 20:15 UTCPublished CVE record published
2026-06-17 03:11 UTCUpdated Record last modified

incomcms project incomcms DOWNGRADE

Affected: 2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison incomcms sudo apt install incomcms=<VERSION_BEFORE_2.0> sudo apt-mark hold incomcms

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

dnf --showduplicates list incomcms sudo dnf downgrade incomcms-<VERSION_BEFORE_2.0> sudo dnf versionlock add incomcms

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · perl-Spreadsheet-XLSX · FIXED · 0.20-1.fc46 · FEDORA-2026-064736b436 · source

sudo dnf upgrade --advisory=FEDORA-2026-064736b436

Fedora ELN · bitcoin-core · FIXED · 32.1-2.eln159 · FEDORA-2026-41e13beebe · source

sudo dnf upgrade --advisory=FEDORA-2026-41e13beebe

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: trhacknon/CVE-2020-29597
Exploit-DB: IncomCMS 2.0 - Insecure File Upload
Nuclei scan template: IncomCMS 2.0 - Arbitrary File Upload

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-2020-29597?

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

Is CVE-2020-29597 being exploited?

CVE-2020-29597 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-2020-29597 affect?

CVE-2020-29597 affects incomcms. Severity is critical (CVSS 9.8). IncomCMS 2.0 has a modules/uploader/showcase/script.php insecure file upload vulnerability. This vulnerability allows unauthenticated attackers to upload files into the server.

How urgent is CVE-2020-29597?

Priority 69/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

References

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