Intel has delivered a stable microcode update for its Broadwell and Haswell processors to mitigate against the Spectre chip flaw.
The company had initially issued firmware updates for machines with its Broadwell, Haswell, Skylake, Kaby Lake, and Coffee Lake processors to address the Spectre/Meltdown chip flaws earlier this year, but was forced to pull the microcode after it caused systems to crash and reboot.
Revised firmware for Skylake, Kaby Lake, and Coffee Lake processors was released last week, but users with Broadwell and Haswell-based machines were left waiting for their own updates.
The updates address variant 2 - the branch injection vulnerability - of the Spectre chip flaw revealed earlier this year.
Intel late last month said it had identified the cause of the issues fot its Broadwell and Haswell platforms and was working on a fix.
Earlier this week it quietly updated its microcode revision guidance document [pdf] to reveal fixes for Broadwell processor versions 50662, 50663, 50664, 40671, 406F1, 306D4 and 40671, and Haswell versions 306C3, 4066, 306F2, 40651 and 306C3 were in production.
Fixes for Sandy Bridge and Ivy Bridge chips are still in beta and being tested by hardware partners.