⚠️Unconfirmed rumours are circulating about wider access to Claude Mythos / Mythos-class models.
I could not find solid proof that this is happening today, despite the rumours spreading across X since yesterday.
But in security, I prefer:
Better Safe Than Sorry
No panic. Just basic wallet hygiene:
1. Check your wallet approvals
2. Revoke old approvals
3. Revoke unlimited approvals
4. Revoke approvals you do not recognise
5. Be careful with DeFi positions you do not actively need exposed
This is especially relevant for lending, yield farming, liquid staking and similar protocols - withdraw your funds to your (hardware) wallet address.
More on revoking wallet approvals here:
x.com/CryptoBobesh/status/20…
Not fear. Just reducing unnecessary attack surface.
I covered the Mythos topic here: 👇
#DeFiSecurity
I exited DeFi in April. This week, two events made me think it was the right call.
Both pointing the same direction. Four days apart.
1) Anthropic's Project Glasswing update (22 May)
Around 50 partners got early access to an unreleased AI model Claude Mythos Preview. In one month:
- 10,000 high or critical vulnerabilities found across partner codebases
- Cloudflare flagged 2,000 bugs, 400 of them serious, with a lower false positive rate than human testers
- Mozilla patched 271 vulns in Firefox 150 with Mythos Preview. That's over 10× what they found in Firefox 148 with Claude Opus 4.6
- UK AI Security Institute: Mythos is the first model to fully solve their end-to-end multi-step cyberattack scenarios
- A partner bank blocked a $1.5M fraudulent wire transfer with help from the model
On 1,000 open-source projects scanned by Anthropic in last few months:
- 6,200 high or critical findings out of 23,019 total
- Of 1,752 reviewed independently, 90.6% confirmed as real bugs and 62.4% confirmed as high or critical
- Some maintainers asked Anthropic to slow down. They cannot patch fast enough.
Of the 530 high or critical bugs Anthropic has disclosed to maintainers so far, only 75 have been patched. Average time to ship a patch: two weeks. Some maintainers asked Anthropic to slow down.
Anthropic's own takeaway: finding bugs is no longer the bottleneck. Verifying, disclosing and shipping patches is.
2) Manuel Aráoz, co-founder of OpenZeppelin (26 May)
He posted that he now considers all of DeFi unsafe and has advised friends and family to exit positions, including blue chips like Aave, Maker and Compound. His argument: coding agents are now superhuman at hunting vulnerabilities, and smart contract security is deeply asymmetric. Defenders must fix every bug. Attackers need one.
Why this hits DeFi harder than most software:
- Smart contract code is public. Attackers pay zero discovery cost.
- Funds live inside the code. No human in the loop to stop an exploit mid-flight.
- Once money moves on-chain, it is gone. No chargeback, no support line.
- A clean audit from six months ago carries less weight than it used to.
To be fair: Glasswing's published numbers were not aimed at smart contracts specifically. We have no hard data yet on how DeFi codebases would score against a Mythos-class model. That gap is part of the warning, not a comfort.
My honest advice:
If you are newer to crypto, or you do not have time to track this space daily, sitting in DeFi at today's yields is a hard trade to defend. If you are experienced, a position cut still looks rational to me. Yields have not moved up to price in this new risk profile.
What would push your view in either direction? Curious what you are watching.