CVE-2026-40323
CVE-2026-40323 is a CWE-345 vulnerability in sp1_sdk. O3 Security confirms whether CVE-2026-40323 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
SP1 V6 Recursion Circuit Row-Count Binding Gap
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40323.
Real-World Exposure
sp1_sdk🦀sp1_recursion_circuit🦀sp1_proverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
SP1 is a zero‑knowledge virtual machine that proves the correct execution of programs compiled for the RISC-V architecture. In versions 6.0.0 through 6.0.2, a soundness vulnerability in the SP1 V6 recursive shard verifier allows a malicious prover to construct a recursive proof from a shard proof that the native verifier would reject. Version 6.1.0 fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | sp1_sdk | ≥ 6.0.0&&< 6.1.0 | 6.1.0 |
| 🦀crates.io | sp1_recursion_circuit | ≥ 6.0.0&&< 6.1.0 | 6.1.0 |
| 🦀crates.io | sp1_prover | ≥ 6.0.0&&< 6.1.0 | 6.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sp1_sdk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update sp1_sdk to 6.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40323 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-40323 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-40323. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-40323 in your dependencies?
O3 detects CVE-2026-40323 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.