Freebsd: >> Freebsd Security Vulnerabilities
The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock. During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.
An unprivileged local user can exploit this use-after-free to escalate privileges.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-27
dsp_mmap_single() validated the requested mapping by checking the sum of the user-supplied offset and length against the buffer size. This addition could overflow, so that a large offset and length wrapped around and passed the check. The offset was then narrowed from 64 to 32 bits when converted to a buffer address, yielding a mapping that extended past the audio buffer into unrelated kernel memory.
The /dev/dsp device nodes are world-accessible by default. On a system with an audio device, either issue allows an unprivileged local user to read and write kernel memory, which can be used to escalate privileges, potentially gaining full control of the affected system. At a minimum, an attacker can crash the kernel, resulting in a Denial of Service (DoS).
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-27
sigqueue(2) was marked as permitted in capability mode with the introduction of Capsicum in 2011, but the implementation of kern_sigqueue did not include a capability mode check restricting signal delivery to the calling process's own PID.
A process in capability mode can use sigqueue(2) to send signals to any process it could signal following standard Unix permissions, bypassing the Capsicum sandbox restriction. A compromised sandboxed process could interfere with other processes, for example by sending SIGKILL or SIGSTOP. This could be any process running as the same user, or any process, for a superuser sandboxed process.
CVSS Score
6.5
EPSS Score
0.001
Published
2026-06-27
When used to deliver a signal to a specific thread, thr_kill2(2) called p_cansignal() to determine whether the operation was permitted but did not check the result before delivering the signal. The signal was sent even when the permission check failed. The system call returned the resulting error to the caller, but by then the signal had already been delivered.
The missing check allows an unprivileged local user who knows or can guess a target's process and thread IDs to send any signal to a process they would not normally be permitted to signal, including processes owned by other users or by root. The same check enforces jail boundaries, so a jailed process can signal processes on the host or in other jails. Thread IDs are allocated globally and sequentially, and so can be discovered by brute force with no visibility into the target.
An attacker can stop or terminate arbitrary processes, including critical system daemons, resulting in a Denial of Service (DoS).
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-26
The KTLS receive path decrypted each record in place, assuming that the mbufs holding received data were anonymous and safe to modify. This assumption does not hold for data placed on a socket by sendfile(2), which can reference file-backed memory directly through non-anonymous M_EXTPG pages or EXT_SFBUF mbufs. When the sender transmits such data over a loopback connection without enabling KTLS on the transmit side, the file-backed mbufs reach the receiver's decryption path unchanged. Decrypting a record in place then overwrites the backing file's page cache instead of a private copy of the data.
An unprivileged local user who can read a file can overwrite its contents with data of their choosing by sending the file over a loopback connection on which they have enabled KTLS receive. The write modifies the page cache directly, so it bypasses file flags such as schg and is written back to disk. By overwriting a setuid binary or other trusted file, a local user can escalate privileges, potentially gaining full control of the affected system.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-26
A file descriptor can be closed while a thread is blocked in a poll(2) or select(2) call waiting for that descriptor. Because the blocked thread does not hold a reference to the underlying object, this closure may result in the object being freed while the thread remains blocked. In this situation, the kernel must remove the blocked thread from the per-object wait queue prior to freeing the object.
In the case of some file descriptor types, the kernel failed to unlink blocked threads from the object before freeing it. When the blocked thread is subsequently woken, it accesses memory that has already been freed resulting in a use-after-free vulnerability.
The use-after-free vulnerability may be triggered by an unprivileged local user and can be exploited to obtain superuser privileges.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-21
When a fusefs file system implements extended attributes, the kernel may send a FUSE_LISTXATTR message to the userspace daemon to retrieve the list of extended attributes for a given file. The FUSE protocol requires the daemon to return a packed list of NUL-terminated strings. The fusefs kernel module calls strlen() on this daemon-supplied buffer without first verifying that the entire list is NUL-terminated.
If a malicious daemon sends a non-NUL-terminated list, the fusefs kernel module may read beyond the end of one heap-allocated buffer and potentially write beyond the end of a second buffer. A malicious daemon could disclose up to 253 bytes of kernel heap memory, or it could inject up to 250 attacker-controlled bytes into unallocated kernel heap space.
CVSS Score
5.5
EPSS Score
0.003
Published
2026-05-21
ptrace(PT_SC_REMOTE) failed to properly validate parameters for the syscall(2) and __syscall(2) meta-system calls. As a result, a user with the ability to debug a process may trigger arbitrary code execution in the kernel, even if the target process has no special privileges.
The missing validation allows an unprivileged local user to escalate privileges, potentially gaining full control of the affected system.
CVSS Score
8.4
EPSS Score
0.002
Published
2026-05-21
In the case of the cap_net service, when a key present in the old limit was omitted from the new limit, the missing key was treated as "allow any" instead of being rejected.
In certain scenarios, an application that had previously restricted a subset of network operations could ask for a new limit that extended the permissions of the process.
CVSS Score
6.5
EPSS Score
0.002
Published
2026-05-21
When bsdinstall or bsdconfig are prompted to scan for nearby Wi-Fi networks, they build up a list of network names and use bsddialog(1) to prompt the user to select a network. This is implemented using a shell script, and the code which handled network names was not careful to prevent expansion by the shell. As a result, a suitably crafted network name can be used to execute commands via a subshell.
The problem can be exploited to execute code as root on the system running bsdinstall or bsdconfig. The attacker would need to create an access point with a specially crafted name and be within range of a Wi-Fi scan. Note that bsdinstall and bsdconfig are vulnerable as soon as the user prompts them to scan for nearby networks; they do not need to actually select the malicious network.
CVSS Score
7.5
EPSS Score
0.003
Published
2026-05-21