CVE-2026-39314: openprinting cups Integer Underflow (Wrap or Wraparound)

Vulnerability summary

CVE-2026-39314 is a medium (CVSS 6.2) Integer Underflow (Wrap or Wraparound) vulnerability in openprinting cups. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 07-04-2026
   PublishedVulnerability first disclosed.
2. 23-06-2026
   Last modifiedVulnerability information updated.

Description

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, an integer underflow vulnerability in _ppdCreateFromIPP() (cups/ppd-cache.c) allows any unprivileged local user to crash the cupsd root process by supplying a negative job-password-supported IPP attribute. The bounds check only caps the upper bound, so a negative value passes validation, is cast to size_t (wrapping to ~2^64), and is used as the length argument to memset() on a 33-byte stack buffer. This causes an immediate SIGSEGV in the cupsd root process. Combined with systemd's Restart=on-failure, an attacker can repeat the crash for sustained denial of service.

• 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.