{"apiVersion":"1.0","identifier":"CVE-2026-99163","description":"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().","publishedAt":"2026-10-28T11:17:36","lastModifiedAt":"2026-10-31T13:17:58","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-99163","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00134,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-99163","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-99163","en":"https://www.redsauce.net/en/cves/CVE-2026-99163","fr":"https://www.redsauce.net/fr/cves/CVE-2026-99163","pt":"https://www.redsauce.net/pt/cves/CVE-2026-99163","de":"https://www.redsauce.net/de/cves/CVE-2026-99163","sk":"https://www.redsauce.net/sk/cves/CVE-2026-99163","el":"https://www.redsauce.net/el/cves/CVE-2026-99163"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-99163"}}