B737-800
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 150; Flight Crew Type 10000
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
Flight Crew FLC Overrode Automation; Flight Crew Returned To Clearance
Aircraft
Climbing out of Denver; the aircraft failed to level off at KIDNG at or below the 10;000 ft. restriction. LNAV and VNAV were selected and MCP showed LNAV/VNAV SPD. The 10;000 ft. restriction was still in the FMC; it was never deleted. I watched it climb right through 10;000 ft. and continue to climb. I punched off the autopilot and pushed us back down to 10;000'. At that point the flight director was obviously holding 10;000 ft.; so I put the autopilot back on and then it started climbing after the KIDNG restriction. We peaked at 10;700 ft. four miles prior to KIDNG. ATC never called us and didn't seem to notice. I didn't write the malfunction up because there were no other problems and that was our third leg in the aircraft. I told the next Captain about the glitch and told him to keep an eye on it.It seems to have been a glitch by the autopilot. I've seen lots of VNAV confusion in the past; but I've never seen it blow through an altitude.
B737 Captain reported the autopilot overshot an assigned altitude during climb.