CVE-2023-26437 Deterred spoofing attempts can lead to authoritative servers being marked unavailable
Attackers can cause denial of service by marking authoritative servers unavailable in PowerDNS Recursor.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-26437?
CVE-2023-26437 is a low-severity denial of service vulnerability in Powerdns Recursor, published on 4 Apr 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Denial of service vulnerability in PowerDNS Recursor allows authoritative servers to be marked unavailable.This issue affects Recursor: through 4.6.5, through 4.7.4 , through 4.8.3.
Weakness: CWE-400
Which versions are affected by CVE-2023-26437?
It affects 1 product.
Linux distribution packages (3)
pdns-recursor SUSE:Package Hub 15 SP4 | All versions | 4.6.6-bp154.2.6.1 |
pdns-recursor openSUSE:Leap 15.4 | All versions | 4.6.6-bp154.2.6.1 |
pdns-recursor openSUSE:Tumbleweed | All versions | 4.8.4-1.1 |
Products include Powerdns Recursor.
How do I fix CVE-2023-26437?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-26437 being exploited?
There is no known exploitation of CVE-2023-26437 in the wild and no public exploit code.
Other vulnerabilities in Powerdns Recursor
- CVE-2009-4009 Memory corruption in n/a
- CVE-2020-10030 Memory corruption in n/a
- CVE-2025-59023 Crafted delegations or IP fragments can poison cached delegations in Recursor
- CVE-2025-59030 Insufficient validation of incoming notifies over TCP can lead to a denial of service in Recursor
- CVE-2023-22617 Denial of service in n/a
Sources
Also known as DEBIAN-CVE-2023-26437, GHSA-4wg5-gmxh-4r2r, UBUNTU-CVE-2023-26437, openSUSE-SU-2023:0101-1, openSUSE-SU-2024:12838-1.