CVE-2026-16517: libarchive Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-16517 is a low (CVSS 2.9) Integer Overflow or Wraparound vulnerability in libarchive. EPSS estimates a 0.08% chance of exploitation in the next 30 days, higher than 0.1% of scored vulnerabilities.

Timeline

1. 21-07-2026
   PublishedVulnerability first disclosed.
2. 21-09-2026
   Last modifiedVulnerability information updated.

Description

A signed integer overflow vulnerability was found in libarchive's ZIP writer. In the archive_write_zip_header function in archive_write_set_format_zip.c, when ZIP encryption is enabled and the entry file size is close to INT64_MAX, the addition of the encryption overhead to the entry size overflows int64_t, resulting in undefined behavior. This could lead to incorrect Zip64 extension decisions or potential memory corruption.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.