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Apple patches iMessage flaw exploited by Pegasus spyware

Apple shipped security updates on 13 September 2021 fixing an iMessage vulnerability that Citizen Lab had found being used to install NSO Group's Pegasus spyware.

Sources: [1][2]

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Apple shipped security updates on 13 September 2021 fixing an iMessage vulnerability that Citizen Lab had found being used to install NSO Group's Pegasus spyware. The researchers said the exploit needed no action by the victim and that they had passed their findings to Apple earlier in September.

Who was responsible

Contribution type and responsibility level for each recorded actor — not sole-author shorthand.

  • Apple

    Organization

    Direct responsibility

    verified

What changed

Fact → Driver → Indicator. Relationship strength orders the paths; it is not the observed indicator movement.

No public driver impacts are listed for this fact.

Evidence

The sources behind this fact and its verification state.

Verified2 sources on file
  1. 1.Apple patches an NSO zero-day flaw affecting all devices - TechCrunchTechCrunch · verified
  2. 2.FORCEDENTRY: NSO Group iMessage Zero-Click Exploit Captured in the Wild - The Citizen LabCitizen Lab · verified

Causal path

How this event connects to drivers and indicators in the graph.

No causal path is recorded: this fact is not linked to a driver.

Articles explaining this fact

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Articles1

Cite this page

Factrail. (2026). Apple patches iMessage flaw exploited by Pegasus spyware. Factrail. https://factrail.ai/facts/apple-patches-pegasus-exploited-zero-click-vulnerability-2021-09-13

https://factrail.ai/facts/apple-patches-pegasus-exploited-zero-click-vulnerability-2021-09-13

Accessed 19 October 2026.

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