Integer overflow in Netatalk

CVE-2026-45698

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 deletedir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. deletedir() 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 prevent buffer overflows by tracking available space in a size_t remain variable. However, the arithmetic used to compute remain results in an unsigned integer underflow, causing the variable to become SIZE_MAX. Because of this, the subsequent boundary check always evaluates as safe, allowing an unbounded strcpy() operation to copy attacker-controlled filenames into a nearly full stack buffer. Version 4.4.3 patches the issue.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45698: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002

Affected products

  • Netatalk — versions >= 3.1.19, < 4.4.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45698?
CVE-2026-45698 is a high-severity vulnerability in Netatalk, classified under Integer Underflow. CVSS score: 7.5/10. Published 2026-08-17.
How severe is CVE-2026-45698?
High severity. CVSS v3 base score is 7.5 out of 10.