tdunning t-digest

• CVE-2026-87962 High 7.5 t-digest 3.1 through 3.3 Denial of Service via Unvalidated Length Fields in MergingDigest.fromBytes 0.6%
• CVE-2026-87822 High 7.5 t-digest 3.1 through 3.3 Denial of Service via NaN Centroid Means in MergingDigest.fromBytes 0.7%