CVE-2020-26131: Issues were discovered in Open DHCP Server (Regular) 1.75 and Open DHCP Server (LDAP Based) 0.1Beta

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HIGH 7.8DOWNGRADE

CVE-2020-26131 is a high-severity flaw (CVSS 7.8) affecting open dhcp server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Issues were discovered in Open DHCP Server (Regular) 1.75 and Open DHCP Server (LDAP Based) 0.1Beta. Due to insufficient access restrictions in the default installation directory, an attacker can elevate privileges by replacing the OpenDHCPServer.exe (Regular) or the OpenDHCPLdap.exe (LDAP Based) binary.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-732
Published	2020-10-28
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: open dhcp server project

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

Am I affected?

Timeline

2020-10-28 18:15 UTCPublished CVE record published
2026-06-17 03:07 UTCUpdated Record last modified

open dhcp server project open dhcp server DOWNGRADE

Affected: 0.1 beta · 1.75

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.1

1. Check installed version

apt-cache policy open-dhcp-server || rpm -q open-dhcp-server || open-dhcp-server --version

2. No fixed release: DOWNGRADE to a release before 0.1 (Debian / Ubuntu)

apt-cache madison open-dhcp-server sudo apt install open-dhcp-server=<VERSION_BEFORE_0.1> sudo apt-mark hold open-dhcp-server

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

dnf --showduplicates list open-dhcp-server sudo dnf downgrade open-dhcp-server-<VERSION_BEFORE_0.1> sudo dnf versionlock add open-dhcp-server

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-2020-26131?

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

Is CVE-2020-26131 being exploited?

CVE-2020-26131 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-2020-26131 affect?

CVE-2020-26131 affects open dhcp server. Severity is high (CVSS 7.8). Issues were discovered in Open DHCP Server (Regular) 1.75 and Open DHCP Server (LDAP Based) 0.1Beta. Due to insufficient access restrictions in the default installation directory, an attacker can elevate privileges by replacing the OpenDHCP

How urgent is CVE-2020-26131?

Priority 41/100. High severity; Public exploit reference

References

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