Direct proof of use
The clearest public proof of 2K12 Kub/SA-6-family use in the 2014 Yemen Civil War is the June 6, 2019 shootdown of a U.S. MQ-9 over Yemen. U.S. Central Command said on June 16, 2019 that the MQ-9 was shot down by what it assessed to be a Houthi SA-6 surface-to-air missile, and added that the altitude of the engagement indicated improved Houthi capability enabled by Iranian assistance.
CSIS later described the same incident in its missile-war study, identifying it as a Houthi-fired SA-6 that shot down a U.S. MQ-9 Reaper reconnaissance drone over Yemen. The report places the missile in a 2K12 Kub/Kvadrat, NATO SA-6 Gainful, section and notes that Yemen had procured at least 200 SA-6 missiles from the Soviet Union in 1979.
Sources: CENTCOM Observation Aircraft Statement, CSIS Missile War in Yemen
Dated milestones
Yemen's prewar inventory is important context but not, by itself, evidence of wartime firing. CSIS reports that Yemen procured at least 200 SA-6 missiles in 1979, creating a legacy stock from which Kub/Kvadrat-family missiles could later appear in the civil war.
On June 6, 2019, a U.S. MQ-9 was shot down over Yemen. CENTCOM's June 16 statement attributed the shootdown to an assessed Houthi SA-6 and treated it as evidence of improved Houthi engagement capability. In August 2019, according to CSIS, the Houthis unveiled the Fater-1 and claimed it was a new indigenous missile, but the report assessed that the displayed missile appeared to be a painted-over SA-6.
A later War Zone review of Houthi air defenses described Fater-1 as at least a copy or clone of the Soviet 3M9 missile for the 2K12 Kub/SA-6 system and reported that Fater-1 missiles were subsequently shown loaded on a Kub launch vehicle. That supports the family identification and display context, while leaving the exact origin of individual missiles unresolved.
Sources: CENTCOM Observation Aircraft Statement, CSIS Missile War in Yemen, War Zone Houthi Air Defenses
Use pattern
The documented conflict role was Houthi-aligned air defense against unmanned aircraft, not a broad record of repeated Kub battery operations. The directly supported firing event is the June 2019 MQ-9 shootdown over Yemen, attributed by CENTCOM to a Houthi SA-6 and by CSIS to a Houthi-fired SA-6.
The public sources separate possession, display, and use. CSIS supports legacy Yemeni SA-6 inventory and the later Fater-1 display; CENTCOM and CSIS support the June 2019 firing against the MQ-9; The War Zone supports the identification of Fater-1 as a 3M9/Kub-family derivative and reports later imagery of Fater-1 on a Kub launcher vehicle. None of the cited sources proves the full launcher, radar, crew structure, or missile origin used in the June 2019 engagement.
Sources: CENTCOM Observation Aircraft Statement, CSIS Missile War in Yemen, War Zone Houthi Air Defenses