OpenBSD CVEs

sys/kern/sysv_sem.c in OpenBSD through 7.9 has a use-after-free allowing local privilege escalation to root. This is a context switch use-after-free after tsleep in sys_semget().

OpenBSD before commit 6a23123 (2026-06-18) contains an out-of-bounds read vulnerability in the mpls_do_error function within sys/netmpls/mpls_input.c that allows remote attackers to disclose kernel stack memory by sending crafted MPLS frames with 16 labels and no Bottom-of-Stack bit set.

Multiple race conditions in the (1) Sudo monitor mode and (2) Sysjail policies in Systrace on NetBSD and OpenBSD allow local users to defeat system call interposition, and consequently bypass access control policy and auditing.

OpenBSD and NetBSD permit usermode code to kill the display server and write to the X.Org /dev/xf86 device, which allows local users with root privileges to reduce securelevel by replacing the System Management Mode (SMM) handler via a write to an SMRAM address within /dev/xf86 (aka the video card memory-mapped I/O range), and then launching the new handler via a System Management Interrupt (SMI), as demonstrated by a write to Programmed I/O port 0xB2.

Integer overflow in banner/banner.c in FreeBSD, NetBSD, and OpenBSD might allow local users to modify memory via a long banner. NOTE: CVE and multiple third parties dispute this issue. Since banner is not setuid, an exploit would not cross privilege boundaries in normal operations. This issue is not a vulnerability

CVS 1.12.x through 1.12.8, and 1.11.x through 1.11.16, does not properly handle malformed "Entry" lines, which prevents a NULL terminator from being used and may lead to a denial of service (crash), modification of critical program data, or arbitrary code execution.

Double free vulnerability for the error_prog_name string in CVS 1.12.x through 1.12.8, and 1.11.x through 1.11.16, may allow remote attackers to execute arbitrary code.

Integer overflow in the "Max-dotdot" CVS protocol command (serve_max_dotdot) for CVS 1.12.x through 1.12.8, and 1.11.x through 1.11.16, may allow remote attackers to cause a server crash, which could cause temporary data to remain undeleted and consume disk space.

serve_notify in CVS 1.12.x through 1.12.8, and 1.11.x through 1.11.16, does not properly handle empty data lines, which may allow remote attackers to perform an "out-of-bounds" write for a single byte to execute arbitrary code or modify critical program data.

Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31 allows remote attackers to cause a denial of service (process crash) and possibly execute arbitrary code via a negative Content-Length HTTP header field, which causes a large amount of data to be copied.

ktrace in BSD-based operating systems allows the owner of a process with special privileges to trace the process after its privileges have been lowered, which may allow the owner to obtain sensitive information that the process obtained while it was running with the extra privileges.

The TCP implementation in various BSD operating systems (tcp_input.c) does not properly block connections to broadcast addresses, which could allow remote attackers to bypass intended filters via packets with a unicast link layer address and an IP broadcast address.

Buffer overflow in BSD line printer daemon (in.lpd or lpd) in various BSD-based operating systems allows remote attackers to execute arbitrary code via an incomplete print job followed by a request to display the printer queue.

Format string vulnerability in OpenBSD yp_passwd program (and possibly other BSD-based operating systems) allows attackers to gain root privileges a malformed name.

Format string vulnerability in OpenBSD su program (and possibly other BSD-based operating systems) allows local attackers to gain root privileges via a malformed shell.

OpenBSD kernel crash through TSS handling, as caused by the crashme program.

OpenBSD crash using nlink value in FFS and EXT2FS filesystems.

Buffer overflow in OpenBSD ping.

rpc.mountd on Linux, Ultrix, and possibly other operating systems, allows remote attackers to determine the existence of a file on the server by attempting to mount that file, which generates different error messages depending on whether the file exists or not.