CVE-2010-3696: The fr_dhcp_decode function in lib/dhcp.c in FreeRADIUS 2.1.9, in certain non-default builds, does not properl

Routine

MEDIUM 4.3DOWNGRADE

CVE-2010-3696 is a medium-severity flaw (CVSS 4.3) affecting freeradius. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The fr_dhcp_decode function in lib/dhcp.c in FreeRADIUS 2.1.9, in certain non-default builds, does not properly handle the DHCP Relay Agent Information option, which allows remote attackers to cause a denial of service (infinite loop and daemon outage) via a packet that has more than one sub-option. NOTE: some of these details are obtained from third party information.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-399
Published	2010-10-07
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: freeradius

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2010-10-07 21:00 UTCPublished CVE record published
2026-06-16 23:23 UTCUpdated Record last modified

freeradius freeradius DOWNGRADE

Affected: 2.1.9

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1.9

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.1.9 (Debian / Ubuntu)

apt-cache madison freeradius sudo apt install freeradius=<VERSION_BEFORE_2.1.9> sudo apt-mark hold freeradius

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

dnf --showduplicates list freeradius sudo dnf downgrade freeradius-<VERSION_BEFORE_2.1.9> sudo dnf versionlock add freeradius

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-2010-3696?

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

Is CVE-2010-3696 being exploited?

CVE-2010-3696 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-2010-3696 affect?

CVE-2010-3696 affects freeradius. Severity is medium (CVSS 4.3). The fr_dhcp_decode function in lib/dhcp.c in FreeRADIUS 2.1.9, in certain non-default builds, does not properly handle the DHCP Relay Agent Information option, which allows remote attackers to cause a denial of service (infinite loop and da

How urgent is CVE-2010-3696?

Priority 34/100. No elevated risk signals yet.

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References

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