Live › vulnerability › CVE-2026-99163
Go to dashboardThe Linux kernel's tracing histogram code accepts an 8-byte signed scalar field where a synthetic stacktrace field is expected, so the scalar is dereferenced as a kernel stacktrace pointer. The sources do not say what an attacker gets beyond that, and the advisory text here gives no privilege or auth details.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-28 11:32 UTC. All times on this page are UTC.
Systems running a Linux kernel with tracing histograms and synthetic events in use, where a user or tool can configure histograms on synthetic stacktrace fields. The sources do not say which kernel versions or configurations are exposed, or whether ordinary unprivileged users can reach the path.
No product ranges from the sources yet.
uname -r to see the running kernel versionEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields
In check_synth_field(), when a synthetic event field is a stacktrace (field->is_stack) and the histogram field is not a "long[" stacktrace array, validation falls through to the generic size and signedness comparison.
Because parse_synth_field() sets a stacktrace field's type to "__data_loc unsigned long[]", its size is sizeof(u64) and synth_field_signed() marks it as signed. Consequently, any 8-byte signed scalar histogram field passes the fallback check, and its scalar value is subsequently dereferenced as a kernel stacktrace pointer in get_field_size() and trace_stack().
Furthermore, checking strstr(hist_field->type, "long[") is insufficient because tracepoint fields defined with __bitmask() or __rel_bitmask() also have type "__data_loc unsigned long[]" or "__rel_loc unsigned long[]", whilst create_hist_field() treats them as 4-byte scalar values without HIST_FIELD_FL_STACKTRACE.
Propagate HIST_FIELD_FL_STACKTRACE to variable references and field variables (whilst excluding variable aliases from per-element stacktrace capture), and reject any mismatch between HIST_FIELD_FL_STACKTRACE and field->is_stack in check_synth_field().
This page as .md · .json · in your agent: get_signal("CVE-2026-99163")
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.