The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - fs: Prevent file descriptor table allocations exceeding INT_MAX When sysctl_nr_open is set to a very high     value (for example, 1073741816 as set by systemd), processes attempting to use file descriptors near the     limit can trigger massive memory allocation attempts that exceed INT_MAX, resulting in a WARNING in     mm/slub.c: WARNING: CPU: 0 PID: 44 at mm/slub.c:5027 __kvmalloc_node_noprof+0x21a/0x288 This happens     because kvmalloc_array() and kvmalloc() check if the requested size exceeds INT_MAX and emit a warning     when the allocation is not flagged with __GFP_NOWARN. Specifically, when nr_open is set to 1073741816     (0x3ffffff8) and a process calls dup2(oldfd, 1073741880), the kernel attempts to allocate: - File     descriptor array: 1073741880 * 8 bytes = 8,589,935,040 bytes - Multiple bitmaps: ~400MB - Total allocation     size: > 8GB (exceeding INT_MAX = 2,147,483,647) Reproducer: 1. Set /proc/sys/fs/nr_open to 1073741816: #     echo 1073741816 > /proc/sys/fs/nr_open 2. Run a program that uses a high file descriptor: #include     <unistd.h> #include <sys/resource.h> int main() { struct rlimit rlim = {1073741824, 1073741824};
    setrlimit(RLIMIT_NOFILE, &rlim); dup2(2, 1073741880); // Triggers the warning return 0; } 3. Observe     WARNING in dmesg at mm/slub.c:5027 systemd commit a8b627a introduced automatic bumping of fs.nr_open to     the maximum possible value. The rationale was that systems with memory control groups (memcg) no longer     need separate file descriptor limits since memory is properly accounted. However, this change overlooked     that: 1. The kernel's allocation functions still enforce INT_MAX as a maximum size regardless of memcg     accounting 2. Programs and tests that legitimately test file descriptor limits can inadvertently trigger     massive allocations 3. The resulting allocations (>8GB) are impractical and will always fail systemd's     algorithm starts with INT_MAX and keeps halving the value until the kernel accepts it. On most systems,     this results in nr_open being set to 1073741816 (0x3ffffff8), which is just under 1GB of file descriptors.
    While processes rarely use file descriptors near this limit in normal operation, certain selftests (like     tools/testing/selftests/core/unshare_test.c) and programs that test file descriptor limits can trigger     this issue. Fix this by adding a check in alloc_fdtable() to ensure the requested allocation size does not     exceed INT_MAX. This causes the operation to fail with -EMFILE instead of triggering a kernel warning and     avoids the impractical >8GB memory allocation request. (CVE-2025-39756)

Note that Nessus relies on the presence of the package as reported by the vendor.

An update of the linux package has been released.

ID	Name	Product	Family	Published	Updated	Severity
264737	Linux Distros Unpatched Vulnerability : CVE-2025-39756	Nessus	Misc.	9/14/2025	9/16/2025	medium
265433	Photon OS 4.0: Linux PHSA-2025-4.0-0864	Nessus	PhotonOS Local Security Checks	9/19/2025	9/19/2025	high

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