The post is light on details, and I agree with the sentiment that it reads like marketing. That said, Opus 4.6 is actually a legitimate step up in capability for security research, and the red team at Anthropic – who wrote this post – are sincere in their efforts to demonstrate frontier risks.
Opus 4.6 is a very eager model that doesn't give up easily. Yesterday, Opus 4.6 took the initiative to aggressively fuzz a public API of a frontier lab I was investigating, and it found a real vulnerability after 100+ uninterrupted tool calls. That would have required lots of of prodding with previous models.
If you want to experience this directly, I'd recommend recording network traffic while using a web app, and then pointing Claude Code at the results (in Chrome, this is Dev Tools > Network > Export HAR). It makes for hours of fun, but it's also a bit scary.
Glad to see that they brought in humans to validate and patch vulnerabilities. Although, I really wish they linked to the actual patches. Here's what I could find:
Yeah, having a layer of human experts to sanity check and weed out hallucinated false positive issues seems like an important part of this process:
> To ensure that Claude hadn’t hallucinated bugs (i.e., invented problems that don’t exist, a problem that increasingly is placing an undue burden on open source developers), we validated every bug extensively before reporting it. [...] for our initial round of findings, our own security researchers validated each vulnerability and wrote patches by hand. As the volume of findings grew, we brought in external (human) security researchers to help with validation and patch development.
Based on the experiences shared by curl's maintainers over the last couple of years, resulting in them ending their bug bounty program [1] [2] [3], I'd suggest the "growing risk of LLM-discovered [security issues]" is primarily maintainers being buried under a deluge of low-effort zero-value LLM-hallucinated false positive security issue reports, where the reporter copy-pastes LLM output without validation.
Grepping for strcat() is at the "forefront of cybersecurity"? The other one that applied a GitHub comment to a different location does not look too difficult either.
Everything that comes out of Anthropic is just noise but their marketing team is unparalleled.
Opus 4.6 is a very eager model that doesn't give up easily. Yesterday, Opus 4.6 took the initiative to aggressively fuzz a public API of a frontier lab I was investigating, and it found a real vulnerability after 100+ uninterrupted tool calls. That would have required lots of of prodding with previous models.
If you want to experience this directly, I'd recommend recording network traffic while using a web app, and then pointing Claude Code at the results (in Chrome, this is Dev Tools > Network > Export HAR). It makes for hours of fun, but it's also a bit scary.
https://cgit.ghostscript.com/cgi-bin/cgit.cgi/ghostpdl.git/c...
https://github.com/OpenSC/OpenSC/pull/3554
https://github.com/dloebl/cgif/pull/84
> To ensure that Claude hadn’t hallucinated bugs (i.e., invented problems that don’t exist, a problem that increasingly is placing an undue burden on open source developers), we validated every bug extensively before reporting it. [...] for our initial round of findings, our own security researchers validated each vulnerability and wrote patches by hand. As the volume of findings grew, we brought in external (human) security researchers to help with validation and patch development.
Based on the experiences shared by curl's maintainers over the last couple of years, resulting in them ending their bug bounty program [1] [2] [3], I'd suggest the "growing risk of LLM-discovered [security issues]" is primarily maintainers being buried under a deluge of low-effort zero-value LLM-hallucinated false positive security issue reports, where the reporter copy-pastes LLM output without validation.
[1] https://daniel.haxx.se/blog/2026/02/03/open-source-security-...
[2] https://daniel.haxx.se/blog/2026/01/26/the-end-of-the-curl-b...
[3] https://daniel.haxx.se/blog/2025/07/14/death-by-a-thousand-s...
Everything that comes out of Anthropic is just noise but their marketing team is unparalleled.