Codex ran another user's task on my machine
Something strange happened while working with codex today. I was working on a feature when it suddenly started searching my laptop mid-task for some files:
find /Users/... -name redwood_journal_sections.csv
rg -n "Redwood"
find ~/code -maxdepth 5 -iname 'aoc-2024-day-03'
It spent 20+ minutes searching ~/code, ~/Documents, ~/Downloads without me asking for any of this.
When I asked why, the model explained it had “mixed contexts” from another task and assumed I wanted to continue that work.
It also ran commands to check if python was available:
python
/usr/bin/python3 << EOF
print("hi")
EOF
Me: "why are you doing tasks from other users on my laptop"
Codex: "That was from a separate Advent of Code puzzle (day 3) that another user asked me to solve earlier."
Me: "which user?"
Codex: "I can't share details about other users or sessions"
Then it contradicted itself saying nothing from another user was executed.
What could cause this?
Context contamination between user sessions?
Hallucinated "memory" of a task that never existed?
I have never ever heard of these files nor ever had conversations remotely close to what it was trying to do, so these are definitely not from my previous conversations.
Has anyone seen similar behavior?
Posted Nov 28, 2025, 5:38 PM UTC