patch · January 19, 2026
Rainbow Six Siege Patch Y10S4.2 Reworks Thorn and Buffs Operators
Tom Clancy's Rainbow Six Siege update Y10S4.2 arrives on January 20th, overhauling Thorn's Razor Bloom Shells with faster triggers and a 15-second movement penalty. The update also returns the Super Shorty to Mozzie, expands Echo's drone pool, and applies targeted buffs to Osaa, Capitao, Lion, Maestro, Jackal, and the UMP45.
Ubisoft deploys Tom Clancy's Rainbow Six Siege update Y10S4.2 on January 20th. The patch shifts Thorn from a niche trapper into an active threat, alongside loadout additions, utility boosts, and bug fixes.
Thorn Reworked for Reactive Play
Thorn receives major adjustments to fix her low round impact. Razor Bloom Shells now activate after a deployment time of 1s, down from 5s. Trigger time after detection drops to 1.35s, down from 2.9s. Max damage decreases to 125 from 180, and the lethal zone is restricted to 0m to 1m from the center. Thorn also starts with 4 shells instead of 3. A successful hit applies a 15-second survivor penalty that causes bleed and slows movement, functioning similarly to Frost's Welcome Mats when self-removed.
Mozzie, Echo, and Operator Buffs
Mozzie regains the Super Shorty shotgun in his secondary loadout slot for the first time since Year 5. Echo gains a third Yokai drone, bringing his total pool to 3. Several operators receive minor tweaks: Osaa's shield deployment drops to 1.8s; Capitao's fire burn duration extends to 13s; Lion's scan duration lengthens to 3s; Maestro's Evil Eye battery life increases to 8s; and Jackal's Eyenox Model III scanning range extends to 12m. The UMP45 damage increases to 42 alongside improved lateral recoil, ensuring a 3-bullet down against base armor types.
Bug Fixes and Quality of Life
The patch resolves multiple gameplay issues, including an outdoor detection bug in the 2F Courtyard Corridor on Fortress and an AI pathing bug where operators failed to pick up a dropped defuser at the base of long stairs. It also fixes unlimited AI contextual pings, vertical recoil limits on the PMR90A2, and unresponsive metal detectors in Kanal's 1F Reception.
Why this patch matters
Y10S4.2 gives Thorn active lethality and disruption, while minor quality-of-life buffs elevate several underpicked defenders and attackers without breaking the core meta.