CVE-2026-33811

A flaw was found in GIMP's PSP file format parser. A double-free condition occurs in the read_layer_block() function when processing a specially crafted PSP file. This could allow an attacker to cause memory corruption, potentially leading to denial of service or arbitrary code execution.

The security fix for CVE-2025-0728 in eclipse-threadx NetX Duo refactors error handling in the HTTP server PUT process to use a shared cleanup label, but this unified cleanup path unconditionally calls fx_file_close() even when the file was never successfully opened. Multiple error branches jump to the shared cleanup label before any file open operation has occurred, causing fx_file_close() to operate on an uninitialized file handle, leading to undefined behavior, double-close issues, or memory corruption.

A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix double free in rxe_srq_from_init In rxe_srq_from_init(), the queue pointer 'q' is assigned to 'srq->rq.queue' before copying the SRQ number to user space. If copy_to_user() fails, the function calls rxe_queue_cleanup() to free the queue, but leaves the now-invalid pointer in 'srq->rq.queue'. The caller of rxe_srq_from_init() (rxe_create_srq) eventually calls rxe_srq_cleanup() upon receiving the error, which triggers a second rxe_queue_cleanup() on the same memory, leading to a double free. The call trace looks like this: kmem_cache_free+0x.../0x... rxe_queue_cleanup+0x1a/0x30 [rdma_rxe] rxe_srq_cleanup+0x42/0x60 [rdma_rxe] rxe_elem_release+0x31/0x70 [rdma_rxe] rxe_create_srq+0x12b/0x1a0 [rdma_rxe] ib_create_srq_user+0x9a/0x150 [ib_core] Fix this by moving 'srq->rq.queue = q' after copy_to_user.

The Zephyr net_buf library (lib/net_buf/buf.c) manipulated both of its reference counts -- the per-header buf->ref and the per-data-block ref_count at the start of each variable/heap data allocation -- with plain non-atomic C operators (buf->ref++, if (--buf->ref > 0), if (--(*ref_count))). The API is documented as self-synchronizing: callers may share one buffer across threads (e.g. via k_fifo) and each holder independently calls net_buf_unref() with no surrounding lock. Under true concurrency (SMP, or single-core preemption between the non-atomic load and store while another context unrefs the same buffer), two holders can both observe the same prior reference value and both conclude they are the last reference. For heap/variable-data pools (mem_pool_data_unref/heap_data_unref, used by zbus message subscribers, the IP stack RX/TX buffers when CONFIG_NET_BUF_FIXED_DATA_SIZE=n, capture, wireguard, ISO-TP and usbip) this produces a double k_heap_free()/k_free() of the same block -- heap-metadata corruption and a use-after-free on the heap-hardening poison pattern. For the per-header refcount the buffer is returned to the pool free LIFO twice for any pool type (including fixed-data pools used by Bluetooth and networking), corrupting the free list so a later allocation hands the same buffer to two owners. The fix converts both refcounts to atomic_inc/atomic_dec (overlaying buf->ref in an atomic_t-sized union and changing the data-block refcount from uint8_t to atomic_t). Impact is gated on genuine concurrency and on an application architecture that shares one buffer among multiple independent unref'ers; the trigger is a refcount/timing race rather than packet content, so an external attacker has at most weak indirect influence over the race window. Affects all Zephyr releases through v4.4.0.

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to 7.1.2-9 and 6.9.13-34, there is a vulnerability in ImageMagick’s Magick++ layer that manifests when Options::fontFamily is invoked with an empty string. Clearing a font family calls RelinquishMagickMemory on _drawInfo->font, freeing the font string but leaving _drawInfo->font pointing to freed memory while _drawInfo->family is set to that (now-invalid) pointer. Any later cleanup or reuse of _drawInfo->font re-frees or dereferences dangling memory. DestroyDrawInfo and other setters (Options::font, Image::font) assume _drawInfo->font remains valid, so destruction or subsequent updates trigger crashes or heap corruption. This vulnerability is fixed in 7.1.2-9 and 6.9.13-34.