CVE-2024-33668: An issue was discovered in Zammad before 6.3.0

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CRITICAL 9.1REMOTEUPGRADE

CVE-2024-33668 is a critical-severity flaw (CVSS 9.1) affecting zammad. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in Zammad before 6.3.0. The Zammad Upload Cache uses insecure, partially guessable FormIDs to identify content. An attacker could try to brute force them to upload malicious content to article drafts they have no access to.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 61%)
CISA exploited list	No
Weakness	CWE-639
Published	2024-04-26
Last modified	2026-09-16

Publisher (CNA): MITRE · Vendor: zammad

Last updated 2026-09-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-04-26 01:15 UTCPublished CVE record published
2026-09-16 20:17 UTCUpdated Record last modified

zammad zammad UPGRADE

Affected: >= 6.2.0 and < 6.3.0 · 6.3.0 alpha

Fixed in: 6.3.0

Safe to downgrade to: a release before 6.2.0

1. Check installed version

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

2. UPGRADE to 6.3.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade zammad

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 6.2.0 (Debian / Ubuntu)

apt-cache madison zammad sudo apt install zammad=<VERSION_BEFORE_6.2.0> sudo apt-mark hold zammad

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

dnf --showduplicates list zammad sudo dnf downgrade zammad-<VERSION_BEFORE_6.2.0> sudo dnf versionlock add zammad

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-2024-33668?

zammad: upgrade to 6.3.0. Exact commands for each OS are on this page.

Is CVE-2024-33668 being exploited?

CVE-2024-33668 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-2024-33668 affect?

CVE-2024-33668 affects zammad. Severity is critical (CVSS 9.1). An issue was discovered in Zammad before 6.3.0. The Zammad Upload Cache uses insecure, partially guessable FormIDs to identify content. An attacker could try to brute force them to upload malicious content to article drafts they have no acc

How urgent is CVE-2024-33668?

Priority 47/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-102489 CRITICAL 9.8 EXPLOITED UPGRADE Zammad GmbH Zammad Session Fixation Vulnerability
CVE-2026-102490 HIGH 7.8 EXPLOITED UPGRADE Zammad GmbH Zammad Improper Privilege Management Vulnerability
CVE-2026-34723 HIGH 7.5 UPGRADE Zammad is a web based open source helpdesk/customer support system
CVE-2026-34724 HIGH 7.2 DOWNGRADE Zammad is a web based open source helpdesk/customer support system
CVE-2026-34721 MEDIUM 6.5 UPGRADE Zammad is a web based open source helpdesk/customer support system

References

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