sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows authentication bypass via certain zero values for lengths.Referenceshttps://blog.argus-systems.ai/blog/openbsd-pap-27-year-auth-bypass.htmlhttps://www.openwall.com/lists/oss-security/2026/06/16/9https://github.com/openbsd/src/commit/076e2b1c1fc4ac0883a72d3544131ad5cee7adf8