---
title: "CVE-2025-24800: ismp-grandpa crate accepted incorrect signatures"
url: https://erroneo.us/security/cve/CVE-2025-24800/
description: "CVE-2025-24800 (ismp-grandpa (crates.io (Rust))): Hyperbridge is a hyper-scalable coprocessor for verifiable, cross-chain interoperability. A critical…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-01-28
date_modified: 2025-01-28
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-24800"
kev: false
cvss: 9.3
epss: 0.00315
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-24800: ismp-grandpa crate accepted incorrect signatures

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.3% , percentile 23: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 23% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes ismp-grandpa (crates.io (Rust)) < 15.0.1, fixed in 15.0.1 ; grandpa-verifier-primitives (crates.io (Rust)) < 0.1.2, fixed in 0.1.2 ; grandpa-verifier (crates.io (Rust)) < 0.1.2, fixed in 0.1.2 . Check your lockfile, including transitive dependencies.

## What it is

Hyperbridge is a hyper-scalable coprocessor for verifiable, cross-chain interoperability. 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. This could be used to steal funds or compromise other kinds of cross-chain applications. This vulnerability is fixed in 15.0.1.

## Affected packages

- crates.io (Rust) `ismp-grandpa` < 15.0.1 → fixed: 15.0.1
- crates.io (Rust) `grandpa-verifier-primitives` < 0.1.2 → fixed: 0.1.2
- crates.io (Rust) `grandpa-verifier` < 0.1.2 → fixed: 0.1.2

## Affected products (CVE record)

- polytope-labs hyperbridge: < 15.0.1

## Severity

- GitHub_M CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.32% probability of exploitation activity in the next 30 days; percentile 23.

## Sources

- [GitHub Advisory GHSA-wwx5-gpgr-vxr7](https://github.com/advisories/GHSA-wwx5-gpgr-vxr7)
- [CVE.org record CVE-2025-24800](https://www.cve.org/CVERecord?id=CVE-2025-24800)
- [NVD entry CVE-2025-24800](https://nvd.nist.gov/vuln/detail/CVE-2025-24800)
- [github.com](https://github.com/polytope-labs/hyperbridge/security/advisories/GHSA-wwx5-gpgr-vxr7)
- [github.com](https://github.com/polytope-labs/hyperbridge/pull/372/commits/f0e85db718f5165b06585a49b14a66f8ad643aea)
- [github.com](https://github.com/polytope-labs/ismp-substrate/pull/64/commits/5ca3351a19151f1a439c30d5cbdbfdc72a11f1a8#diff-3835cc24fb2011b3e8246036059acd8c2c2a9a869eedf7a210d18edb6543318dL262)
- [github.com](https://github.com/polytope-labs/ismp-substrate/pull/64/commits/04d5be207b082eb61d586d52e1685e2e060347e6#diff-4aedbca82d26bebc03f274e23fd5697c3346ffff54405c87af9018f3aef708b2R1-R160)
- [github.com](https://github.com/polytope-labs/ismp-substrate/pull/64/commits/b26894913b301061b07db61af841ca2586415f08#diff-493a6129d75fe31185e28695a4d2adc1582fe9df12462e380fe994f170fc1e70L159)

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Source page: https://erroneo.us/security/cve/CVE-2025-24800/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt