Week in review: Claude Mythos finds 271 Firefox flaws, Vercel breach

2026-04-26T08:51:44Z9beccd498bab48df375073dba021cf715c47a7ee86b7fd2cbcfbcad6f61fa7e3
Android privacyCI/CD securityChina threat actorsCisco FirepowerFirefox vulnerabilitiesFirestarterLLM securityMeta AccountNFC malwareOpenAI GPT-5.5SmokedMeatUbuntu 26.04Vercel breachauthenticationbotnetsfirewall backdoormemory-safepasskeysprompt injectionrouters

What happened

Weekly intelligence roundup: multiple high-impact items including a persistent state‑sponsored backdoor (“Firestarter”) observed on Cisco Firepower/Secure Firewall appliances that in some cases can only be removed by powering the device off; the UK NCSC advising consumers to replace passwords with passkeys; growing real‑world abuse of indirect prompt injection against LLM agents; China‑linked espionage shifting to large botnets of compromised routers and edge devices; reports of 271 Firefox flaws (Claude Mythos) and a Vercel breach; new offensive/defensive tooling (SmokedMeat) for CI/CD attack

Why it matters

A reviewed impact interpretation has not been published for this record.

Evidence and limitations

Source ID
helpnetsecurity
Record identifier
9beccd498bab48df375073dba021cf715c47a7ee86b7fd2cbcfbcad6f61fa7e3
Enrichment time
2026-04-26T08:51:44Z
AI-assisted enrichment
Yes

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Record · Week in review: Claude Mythos finds 271 Firefox flaws, Vercel breach · Baitaphish