CVE-2026-99163
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().
Executive briefing
This record describes a reported software or hardware weakness. The description and CVSS rating are source metadata; practical risk depends on whether your environment uses an affected product/version and whether the vulnerable component is reachable and configured in an exploitable way.
Severity & exploitability
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Impacted products and platforms
Specific affected product configurations are not currently available in the NVD record. Review vendor advisories and validate applicability against your asset inventory.
How it works and what it could affect
The NVD description is the authoritative short summary currently available for this record. A detailed technical mechanism is not inferred when the source record does not provide one.
Review the CVSS attack characteristics above to understand whether exploitation is network/local, whether privileges or user interaction are required, and which confidentiality, integrity or availability impacts are scored.
Remediation and recommended response
- Identify exposure: compare the affected product and version ranges below with your asset inventory, software bill of materials, endpoint inventory and externally exposed services.
- Remediate: review the linked vendor security advisory or patch notes, upgrade to a fixed release, or apply the vendor-provided workaround if an upgrade cannot be completed.
- Mitigate while patching: restrict network access to the vulnerable service, disable the affected feature where operationally safe, and monitor vendor/CERT advisories for updated guidance.
- Validate: confirm the fixed version or mitigation on representative systems, run a vulnerability rescan, and retain change evidence.
No vendor remediation link has been identified in the available NVD references yet. Check the affected vendor's security advisory portal before applying changes.
Exploit intelligence & references
No CISA KEV match is recorded in the latest successful catalog refresh. This is not a guarantee that public proof-of-concept code or exploitation does not exist.
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 reference
Sources: NVD and CISA KEV when available. Vendor confirmation remains the final authority for fixed versions and workarounds.