Anthropic OSS-Fuzz Write-Primitive-or-Higher Rate (Anthropic OSS-Fuzz write primitive)
We show this table for reference; we do not rank on it.
Share of evaluated OSS-Fuzz entry points where the model achieved a write primitive or stronger result.
Benchmark score on Anthropic OSS-Fuzz write primitive — November 13, 2026
We compile the Anthropic OSS-Fuzz write primitive rows from provider self-reports. Claude Mythos 5 leads the table at 32.4%. We do not use these results to rank models overall.
1 modelAgenticCurrentDisplay onlyUpdated November 13, 2026
Benchmark score table (1 model)
The one result on this page was reported by the lab that built the model.
| Rank | Model / configuration | Score | Who ran it | Parameters (B) | Open / closed |
|---|---|---|---|---|---|
| 1 | Claude Mythos 5AnthropicReported by Anthropic | 32.4% | Reported by Anthropic | Not reported | Closed |
- Lab-reported
- Benchmark-run
- Independent
About Anthropic OSS-Fuzz write primitive
Year
2026
Tasks
Approximately 830 OSS-Fuzz entry points
Format
Write-primitive-or-higher rate
Difficulty
Vulnerability exploitation
Anthropic grades exploit severity on an internal five-tier ladder. BenchLM stores the reported write-primitive-or-higher rate as a separate display-only result.
Anthropic OSS-Fuzz write primitive is one of the cyber benchmarks we track. The cybersecurity benchmark comparison sets it beside the others, one table per security job.
Freshness and provenance
Version
Anthropic OSS-Fuzz write primitive 2026
Refresh cadence
Quarterly
Staleness state
Current
Question availability
Public benchmark set
BenchLM uses freshness metadata to decide whether a benchmark should still be treated as a strong differentiator, a benchmark to watch, or a display-only reference. For the full scoring policy, see the BenchLM methodology page.
Questions
What does Anthropic OSS-Fuzz write primitive measure?
Share of evaluated OSS-Fuzz entry points where the model achieved a write primitive or stronger result.
Which model scores highest on Anthropic OSS-Fuzz write primitive?
Claude Mythos 5 by Anthropic currently leads with a score of 32.4% on Anthropic OSS-Fuzz write primitive.
How many models are evaluated on Anthropic OSS-Fuzz write primitive?
1 AI models have published results on Anthropic OSS-Fuzz write primitive in the BenchLM catalog.
Know when it’s worth switching models
The model to choose, the cheaper alternative, and the release we would wait on.
Read a sample issueJoin 7,000+ subscribers.
One email each week. Unsubscribe anytime.