The mkdir procedure of GNU Guile temporarily changed the process' umask to zero. During that time window, in a multithreaded application, other threads could end up creating files with insecure permissions. For example, mkdir without the optional mode argument would create directories as 0777. This is fixed in Guile 2.0.13. Prior versions are affected.
Severity
CVSS 3.0
5.3 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
2.8% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-31)