Home › CVE Intelligence › CVE-2026-55407
CVSS 8.0 HIGH 🔴 ACTIVELY EXPLOITED Zero-Day Exploit

CVE-2026-55407: 22x memory amplification bug in Anthropic's buffa protobuf decoder

<table> <tr><td> <a href="https://www.reddit.com/r/cybersecurity/comments/1uk77yw/cve202655407_22x_memory_amplification_bug_in/"> <img src="https://external-preview.redd.it/BLhe…

8.0CVSS Score
HIGHSeverity
NOCISA KEV
Zero-Day ExploitImpact Type

📋 Vulnerability Details

CVE IDCVE-2026-55407
Vendorreddit_cyber
Affected ProductThreat Intelligence
Vulnerability TypeZero-Day Exploit
CVSS Score8.0 (HIGH)
Actively Exploited✅ Yes
Patch StatusSee Vendor Advisory →
Reported ByCYBERDUDEBIVASH SENTINEL APEX Intelligence (via reddit_cyber)

🔬 Technical Analysis

<table> <tr><td> <a href="https://www.reddit.com/r/cybersecurity/comments/1uk77yw/cve202655407_22x_memory_amplification_bug_in/"> <img src="https://external-preview.redd.it/BLheNygch3iC0QltsGzZbLlNGNicgKIiRcsMYssmlzU.png?width=640&crop=smart&auto=webp&s=755931bebe50a0f080c5800f60a02a07655e3159" alt="CVE-2026-55407: 22x memory amplification bug in Anthropic's buffa protobuf decoder" title="CVE-2026-55407: 22x memory amplification bug in Anthropic's buffa protobuf decoder" /> </a> </td><td>   submitted by   <a href="https://www.reddit.com/user/bugvader25"> /u/bugvader25 </a> <br/> <span><a href="https://www.endorlabs.com/lea

🎯 Known Indicators of Compromise

{"type":"sha1","value":"755931bebe50a0f080c5800f60a02a07655e3159","confidence_score":0.9,"first_seen":"2026-07-01","source_count":1} {"type":"url","value":"https://www.reddit.com/r/cybersecurity/comments/1uk77yw/cve202655407_22x_memory_amplification_bug_in","confidence_score":0.82,"first_seen":"2026-07-01","source_count":1} {"type":"url","value":"https://external-preview.redd.it/BLheNygch3iC0QltsGzZbLlNGNicgKIiRcsMYssmlzU.png?width=640&c","confidence_score":0.82,"first_seen":"2026-07-01","source_count":1} {"type":"url","value":"https://www.reddit.com/user/bugvader25">","confidence_score":0.82,"first_seen":"2026-07-01","source_count":1} {"type":"url","value":"https://www.endorlabs.com/learn/endor-labs-ai-sast-finds-zero-day-cve-2026-55407-buffa">[lin","confidence_score":0.82,"first_seen":"2026-07-01","source_count":1} {"type":"domain","value":"www.reddit.com","confidence_score":0.75,"first_seen":"2026-07-01","source_count":1} {"type":"domain","value":"www.endorlabs.com","confidence_score":0.75,"first_seen":"2026-07-01","source_count":1}

📚 Advisory References

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