CVE-2026-44069: Netatalk Information Disclosure Flaw

CVE-2026-44069 Overview

CVE-2026-44069 is an integer underflow vulnerability [CWE-191] in the volxlate function of Netatalk, an open-source implementation of the Apple Filing Protocol (AFP). The flaw affects Netatalk versions 3.0.0 through 4.4.2. A local privileged user can supply crafted volume translation input that triggers the underflow during processing.

Successful exploitation allows limited information disclosure, limited data modification, or a minor service disruption on the affected host. The vulnerability requires local access and existing high privileges, which constrains its practical impact.

Critical Impact

A local authenticated attacker with high privileges can exploit the volxlate integer underflow to read limited information, modify limited data, or cause minor service disruption in Netatalk 3.0.0 through 4.4.2.

Affected Products

• Netatalk 3.0.0 through 4.4.2
• Systems running AFP file sharing services via Netatalk
• Linux and Unix distributions packaging vulnerable Netatalk releases

Discovery Timeline

• 2026-05-21 - CVE CVE-2026-44069 published to NVD
• 2026-05-21 - Last updated in NVD database

Technical Details for CVE-2026-44069

Vulnerability Analysis

The vulnerability resides in the volxlate function within Netatalk, which performs volume translation operations for AFP shares. An integer underflow occurs when crafted input causes an arithmetic operation to wrap below the minimum representable value of the target integer type. This produces an unexpectedly large unsigned value that is then used in subsequent processing.

The condition is reachable only by a local user who already holds high privileges on the host. The resulting memory access or control-flow deviation is constrained, which is why the recorded confidentiality, integrity, and availability effects are limited rather than full compromise.

Root Cause

The root cause is missing or incorrect validation of integer operands inside volxlate before arithmetic that can underflow [CWE-191]. When a signed subtraction or unsigned decrement passes the lower bound, the resulting value diverges from the developer's expected range and is consumed by length, index, or offset logic downstream.

Attack Vector

Exploitation requires local access, high attack complexity, and high existing privileges. The attacker submits crafted volume translation input to a Netatalk process they can already interact with. No user interaction is required. The scope remains unchanged, meaning impact is bounded to the same security authority as the vulnerable component.

No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Netatalk Security Advisory for technical specifics.

Detection Methods for CVE-2026-44069

Indicators of Compromise

• Unexpected crashes, restarts, or abnormal termination of the afpd or related Netatalk daemons.
• Anomalous volume translation entries or malformed configuration values supplied to Netatalk by local users.
• Audit log entries showing privileged local users invoking Netatalk administrative operations outside of normal change windows.

Detection Strategies

• Inventory all hosts running Netatalk and compare installed versions against the vulnerable range 3.0.0 through 4.4.2.
• Monitor process telemetry for abnormal exits, signal-based terminations, or core dumps originating from Netatalk binaries.
• Review system audit logs for privileged operations interacting with AFP volume configuration on internet-exposed or multi-tenant hosts.

Monitoring Recommendations

• Enable verbose Netatalk logging to capture volume translation parsing errors and abnormal input handling.
• Forward host process and authentication telemetry to a centralized analytics platform for correlation with privilege use.
• Alert on repeated Netatalk daemon restarts on the same host within a short time window.

How to Mitigate CVE-2026-44069

Immediate Actions Required

• Upgrade Netatalk to a fixed release published after 4.4.2 as listed in the Netatalk Security Advisory.
• Restrict local shell and administrative access to hosts running Netatalk to a minimal set of trusted operators.
• Audit which accounts hold the high privileges required to interact with volxlate input paths and revoke unnecessary access.

Patch Information

The Netatalk project has published a security advisory for CVE-2026-44069. Administrators should consult the Netatalk Security Advisory for the specific fixed version and upgrade instructions. Distribution maintainers typically backport such fixes; verify that the packaged Netatalk version on each host includes the corresponding patch.

Workarounds

• Disable Netatalk services on hosts that do not require AFP file sharing until patching is complete.
• Limit Netatalk volume configuration changes to a single administrative account and log all modifications.
• Apply operating system hardening to reduce the number of local privileged users on AFP servers.

# Verify installed Netatalk version and disable the service if unused
afpd -V
systemctl stop netatalk
systemctl disable netatalk