PatchTheCVECVE-2026-33597: PRSD detection denial of service
25
Routine
LOW 3.7REMOTEUPGRADE
CVE-2026-33597 is a low-severity flaw (CVSS 3.7) affecting dnsdist. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
PRSD detection denial of service
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 3.7 (Low) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 72%) |
| CISA exploited list | No |
| Weakness | CWE-116 |
| Published | 2026-04-22 |
| Last modified | 2026-10-26 |
Publisher (CNA): Open-Xchange · Vendor: powerdns
Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
powerdns dnsdist UPGRADE
Affected: >= 1.9.0 and < 1.9.13 · >= 2.0.0 and < 2.0.4
Fixed in: 1.9.13, 2.0.4
Safe to downgrade to: a release before 1.9.0
1. Check installed version
apt-cache policy dnsdist || rpm -q dnsdist || dnsdist --version
2. UPGRADE to 1.9.13 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade dnsdist
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade dnsdist
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 1.9.0 (Debian / Ubuntu)
apt-cache madison dnsdist
sudo apt install dnsdist=<VERSION_BEFORE_1.9.0>
sudo apt-mark hold dnsdist
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list dnsdist
sudo dnf downgrade dnsdist-<VERSION_BEFORE_1.9.0>
sudo dnf versionlock add dnsdist
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.
Quick answers
How do I fix CVE-2026-33597?
dnsdist: upgrade to 1.9.13, 2.0.4. Exact commands for each OS are on this page.
Is CVE-2026-33597 being exploited?
CVE-2026-33597 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-2026-33597 affect?
CVE-2026-33597 affects dnsdist. Severity is low (CVSS 3.7). PRSD detection denial of service
How urgent is CVE-2026-33597?
Priority 25/100. Remotely exploitable, no login, no user action
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