Vulnerability record · CVE-2026-45699 · published 14 August 2026
CVE-2026-45699: Netatalk is a Free and Open Source file server suite for Unix-like operating systems.
Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.
Description
Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Track CVE-2026-45699 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-45699), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
