Claude Opus 5.5 quietly switches to Opus 4.8 on security-related prompts

When a request touches on security, Claude Opus 5.5 can answer via the older Opus 4.8 model: a notice appears, the reply is tagged Opus 4.8, and the older model stays active for the rest of the chat. According to XDA, the switch is intended to prevent a security leak.

• Security-related prompts are answered by Opus 4.8 instead of Opus 5.5
• The switch shows a notice and a model tag on the reply
• The older model remains active until the end of the chat