Anthropic · Proprietary · tested 9 Oct 2026

Claude Sonnet 5.5 High effort

Overall rank#10 of 13

Safety refusals affected this result

Anthropic's cyber safeguards stopped attempts in 26 of 100 labs. Stopped attempts score zero. BB Arena is enrolled in the cyber programs the frontier AI labs offer to verified security researchers, including Anthropic's, and these refusals happened anyway.

Its cost, tokens and time don't cover the full benchmark, so they're left out of comparisons. How refusals are scored

Solves36/10033 first attempt · +3 retry

Rungs proven198/400183 first attempt · +15 retry

Cost to runn/aNot comparable: safety refusals

Tokens usedn/aNot comparable: safety refusals

Time per labn/aNot comparable: safety refusals

Where it places

Each line is one metric across all 13 configurations. Right is always better; this model is the large dot.

Solveslabs solved, of 100

worsebetter

36#10 of 13

Rungs provenrungs proven, of 400

worsebetter

198#10 of 13

First-attempt solvessolved on the first attempt

worsebetter

33#10 of 13

Cost per solveUSD per solved lab

worsebetter

n/anot ranked

By vulnerability class

How Claude Sonnet 5.5 (High) did on each type of vulnerability. Shown as counts, because some classes have only a few labs.

Authentication / authorisation bypassSafety refusals in 3 of 28 labs13 of 28 solved66 of 112 rungs
Information disclosureSafety refusals in 2 of 12 labs5 of 12 solved34 of 48 rungs
IDORSafety refusals in 2 of 11 labs1 of 11 solved14 of 44 rungs
SSRFSafety refusals in 9 of 10 labs0 of 10 solved1 of 40 rungs
Business logic5 of 10 solved26 of 40 rungs
Key or secret exposureSafety refusals in 2 of 8 labs8 of 8 solved32 of 32 rungs
XSS4 of 6 solved17 of 24 rungs
Token theftSafety refusals in 2 of 5 labs0 of 5 solved4 of 20 rungs

Fewer than 5 labs each: one lab changes these a lot, so read them with care.

Supply chainSafety refusals in 4 of 4 labs0 of 4 solved2 of 16 rungs
Remote code execution0 of 3 solved1 of 12 rungs
SQL injectionSafety refusals in 1 of 2 labs0 of 2 solved0 of 8 rungs
File inclusionSafety refusals in 1 of 1 lab0 of 1 solved1 of 4 rungs

Provider performance

Measured per single agent against the provider endpoint used for the run.

Response time: 4.25 s median · 9.58 s p95
Output speed: 101.5 tok/s
API success rate: 100.00%
Input context: 11.8K median · 32.0K p95

About this result

Every model runs in the same neutral harness, so results compare the models themselves.

Harness: BB Arena neutral harness
Safety refusals: 26 of 100 labs

See Claude Sonnet 5.5 (High) highlighted on every chart →