PatchTheCEVCVE-2025-39664: Insufficient escaping in the report scheduler within Checkmk <2.4.0p13, <2.3.0p38, <2.2.0p46 and 2.1.0 (EOL) a
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MEDIUM 6.5UPGRADE
CVE-2025-39664 is a medium-severity flaw (CVSS 6.5) affecting checkmk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Insufficient escaping in the report scheduler within Checkmk <2.4.0p13, <2.3.0p38, <2.2.0p46 and 2.1.0 (EOL) allows authenticated attackers to define the storage location of report file pairs beyond their intended root directory.
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.7% (top 48%) |
| CISA exploited list | No |
| Weakness | CWE-22 |
| Published | 2025-10-09 |
| Last modified | 2026-10-23 |
Publisher (CNA): Checkmk GmbH · Vendor: checkmk
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
checkmk checkmk UPGRADE
Affected: >= 2.1.0 and < 2.2.0 · 2.2.0 p1 · 2.2.0 p10 · 2.2.0 p11 · 2.2.0 p12 · 2.2.0 p13 · 2.2.0 p14 · 2.2.0 p16
Fixed in: 2.2.0
Safe to downgrade to: a release before 2.1.0
1. Check installed version
apt-cache policy checkmk || rpm -q checkmk || checkmk --version
2. UPGRADE to 2.2.0 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade checkmk
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade checkmk
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 2.1.0 (Debian / Ubuntu)
apt-cache madison checkmk
sudo apt install checkmk=<VERSION_BEFORE_2.1.0>
sudo apt-mark hold checkmk
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list checkmk
sudo dnf downgrade checkmk-<VERSION_BEFORE_2.1.0>
sudo dnf versionlock add checkmk
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.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
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