New Interrupt Injection Flaw Bypasses Spectre v2 Defenses on Major CPUs
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CAMBRIDGE, Mass. — Additional corroborating reports have emerged regarding the Interrupt Injection vulnerability affecting Intel and AMD processors previously identified by MIT researchers. These new accounts confirm that attackers can successfully manipulate hardware interrupts to bypass Spectre v2 defenses across a broader range of systems than initially assessed. The findings reinforce the critical nature of the flaw detailed on Aug. 6, suggesting that existing mitigation strategies may be insufficient against this specific attack vector in various enterprise and consumer environments. Security teams are now advised to prioritize patching efforts as evidence mounts regarding the exploit's practical feasibility outside controlled laboratory settings. While no new technical mechanisms have been disclosed beyond the original timing gap exploitation, the volume of independent confirmations indicates a widespread potential for data leakage through compromised interrupt handling routines.
CAMBRIDGE, Mass. — Researchers at the Massachusetts Institute of Technology have identified a critical security vulnerability in Intel and AMD processors that allows attackers to bypass existing defenses against Spectre variant 2 attacks by manipulating hardware interrupts.
Daniël Trujillo and Mengjia Yan from MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) detailed the flaw, termed "Interrupt Injection," on Aug. 6, 2026. The vulnerability exploits a timing gap between when a processor sanitizes its branch predictor state and when the operating system kernel utilizes that same hardware component.
The attack works by precisely timing the injection of hardware interrupts to re-poison the branch predictors immediately after they have been cleared by security mitigations. This technique effectively resets the protective measures, allowing malicious code to leak arbitrary data from protected kernel memory space. Spectre v2 defenses were originally designed to prevent unauthorized access to speculative execution paths, but this new method circumvents those safeguards without requiring direct hardware modification or physical access.
The discovery highlights a persistent challenge in securing modern high-performance computing architectures against side-channel attacks. By leveraging the timing of interrupts, attackers can force CPUs into an insecure state where branch prediction logic is manipulated before it can be safely utilized by legitimate system processes. The flaw affects both Intel and AMD central processing units, impacting a vast array of devices ranging from personal laptops to enterprise servers.
Trujillo and Yan demonstrated that the exploit does not rely on software bugs within specific applications but rather targets fundamental hardware behaviors shared across processor generations. This distinction makes patching difficult, as it requires changes at the microcode level or significant architectural adjustments by chip manufacturers. The researchers noted that current operating system mitigations assume a static environment between sanitization and usage, an assumption this attack directly invalidates.
Industry experts are now assessing the scope of potential impact across global infrastructure. While no widespread exploitation has been confirmed in public networks as of Aug. 6, the theoretical capability to extract sensitive encryption keys or user credentials raises immediate concerns for cybersecurity teams worldwide. Chipmakers have not yet released official statements regarding timelines for patches or microcode updates.
The research team emphasized that while the attack vector is sophisticated, it represents a significant evolution in speculative execution vulnerabilities. Questions remain regarding how quickly vendors can deploy effective countermeasures without degrading system performance further, as previous Spectre mitigations already incurred measurable speed penalties. The cybersecurity community now watches closely for vendor responses and potential proof-of-concept demonstrations that could validate the severity of the threat.