The vulnerability occurs in systemd, the system and service manager used as the init process on Linux hosts. An unprivileged user can trigger a defensive assert, or on older releases (v249 and earlier) a stack overwrite, by making a special IPC API call with malformed data. The assert causes the process to freeze, creating a denial‑of‑service condition. In the vulnerable older versions the memory corruption could allow an attacker to execute arbitrary code, provided a suitable exploitation path can be constructed. The weakness is classified as CWE‑1287 (Incorrect Processing of Dangling Users Input) and CWE‑269 (Improper System Permissions for a Resource).

Affected installations are those running systemd version 239 through 249 that have not applied the later safety check. From version v250 onward the unsafe path has been replaced by a failsafe assert, preventing the overwrite. The patch set is present in releases 260‑rc1, 259.2, 258.5, and 257.11. Systems that use older or maintenance‑branch versions of systemd remain susceptible, and because systemd typically runs as PID 1 the fault directly impacts the host's core services.

The CVSS score for this issue is 5.5, indicating medium severity. The EPSS score is less than 1%, indicating a low probability of exploitation. The vulnerability is not listed in CISA’s KEV catalog, so no widespread active exploitation has been reported. An adversary could cause service interruption or, in the case of legacy releases, potentially gain unprivileged code execution through stack corruption.