CVE-2025-24800 — ismp-grandpa
Fix: polytope-labs/hyperbridge#372CVE-2025-24800 is a CWE-347 vulnerability in ismp-grandpa. A fix is available for ismp-grandpa — see the affected versions and patch details below.
Critical vulnerability in `ismp-grandpa` <v15.0.1
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2025-24800.
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
ismp-grandpa🦀grandpa-verifier-primitives🦀grandpa-verifierReal-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
A critical vulnerability was discovered in the ismp-grandpa crate, that allowed a malicious prover easily convince the verifier of the finality of arbitrary headers.
Description
The vulnerability manifests as a verifer that only accepts incorrect signatures of Grandpa precommits and was introduced in this specific commit. Perhaps due to unfamiliarity with core substrate APIs. The if statement should have included a negation check, similar to the previous code, but this was omitted. Causing the verifier to only accept invalid signatures.
This vulnerability remained undetected even with integration tests, as the prover was also misconfigured to initialize the Grandpa verifier with the incorrect authority set_id. This causes verification of honest precommit signatures to fail as the message is now malformed, but the verifier indeed only accepts signatures or messages that fail the verification check.
But even more devastatingly, the verifier will also accept malicious GRANDPA signatures for any precommit message.
This vulnerability has been fixed in this commit and a patch release has been published.
Impact
This could be used to steal funds or compromise other kinds of cross-chain applications.
Patches
This vulnerability has been fixed in the latest version of ismp-granpda v15.0.1
Recommendations
Users who rely on the compromised versions must upgrade immediately, as all vulnerable versions of the crate has been yanked.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | ismp-grandpa | all versions | 15.0.1cargo update -p ismp-grandpa --precise 15.0.1 |
| 🦀crates.io | grandpa-verifier-primitives | all versions | 0.1.2cargo update -p grandpa-verifier-primitives --precise 0.1.2 |
| 🦀crates.io | grandpa-verifier | all versions | 0.1.2cargo update -p grandpa-verifier --precise 0.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ismp-grandpa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ismp-grandpa to 15.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-24800 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-24800 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-24800. 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-2025-24800 in your dependencies?
O3 Security finds CVE-2025-24800 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.