CVE-2026-39314

CVE-2026-39314 is an integer underflow vulnerability affecting OpenPrinting CUPS versions 2.4.16 and prior, located in the _ppdCreateFromIPP() function within cups/ppd-cache.c. The flaw allows unprivileged local users to crash the cupsd root process by supplying a negative value for the job-password-supported IPP attribute. The vulnerability stems from incomplete bounds validation that only checks the upper limit, permitting negative values to pass through, which are then cast to size_t and used in a memset() call on a 33-byte stack buffer, triggering immediate segmentation faults. The attack requires local access but demands no special privileges, elevated complexity, or user interaction. The CVSS score of 6.2 (Medium) reflects the availability impact severity. When combined with systemd's automatic restart functionality, an attacker can sustain denial of service through repeated crash cycles, effectively disabling the printing system on affected Linux and Unix-like systems. Currently, this vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog and shows no evidence of active exploitation in the wild. The EPSS score of 0.00016 places this in the lower percentile of exploit probability across all CVEs. The Faucet Risk Score of 44.0/100 indicates moderate concern, but the lack of public exploit code and community attention suggests limited immediate threat. Organizations should prioritize patching based on their CUPS deployment footprint and local user access controls.