netatalk.io

Netatalk Security Advisory

Subject Pre-authentication DSI frame smuggling
CVE ID# CVE-2026-62320
Severity Medium
Disclosure Date 2026/07/16
Affected Versions 1.5.0-4.5.0
Summary Oversized DSI frames leave attacker-controlled bytes queued for the next receive operation

Description

The pre-authentication DSI listener truncates oversized frame payloads without rejecting or draining them. An unauthenticated remote attacker can leave residual bytes in the TCP stream to be parsed as additional DSI frames.

Patch Availability

Apply CVE-2026-62319,CVE-2026-62320.patch to a Netatalk 4.5.0 source tree to hotfix your local Netatalk deployment.

Alternatively, upgrade to Netatalk 4.5.1 or later, which includes the patch.

Netatalk administrators are advised to upgrade to this version or apply the patch as soon as possible.

CVSS Calculation

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N (6.9)

Workaround

Restrict access to AFP port 548 to trusted networks using firewall rules until patched.

Credits

Vulnerability reported by:

Alejandro Ramos aramosf@gmail.com

Patch developed by:

Daniel Markstedt of the Netatalk team

References


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