CVE-2026-45698: netatalk Integer Underflow (Wrap or Wraparound)

Vulnerability summary

CVE-2026-45698 is a high (CVSS 7.5) Integer Underflow (Wrap or Wraparound) vulnerability in netatalk. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.8% of scored vulnerabilities.

Timeline

1. 17-08-2026
   PublishedVulnerability first disclosed.
2. 17-08-2026
   Last modifiedVulnerability information updated.

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 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.

• CWE-191Integer Underflow (Wrap or Wraparound)The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.