CVE-2026-46654
CVE-2026-46654 is a CWE-345 vulnerability in p3-challenger. O3 Security confirms whether CVE-2026-46654 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Plonky3 MultiField32Challenger: transcript malleability and challenge entropy loss
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-2026-46654.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
p3-challenger🦀p3-challengerReal-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
Plonky3 is a toolkit for polynomial IOPs (PIOPs). Prior to versions 0.4.3 and 0.5.3, an attacker controlling prover-side observations can craft distinct transcripts that produce identical challenges, breaking the binding property of Fiat-Shamir. This issue has been patched in versions 0.4.3 and 0.5.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | p3-challenger | all versions | 0.4.3 |
| 🦀crates.io | p3-challenger | ≥ 0.5.0&&< 0.5.3 | 0.5.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for p3-challenger. 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 p3-challenger to 0.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46654 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-2026-46654 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-2026-46654. 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-2026-46654 in your dependencies?
O3 detects CVE-2026-46654 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.