---
title: "CVE-2025-9287: cipher-base is missing type checks, leading to hash rewind and passing on crafted data"
url: https://erroneo.us/security/cve/CVE-2025-9287/
description: "CVE-2025-9287 (cipher-base (npm)): Improper Input Validation vulnerability in cipher-base allows Input Data Manipulation.This issue affects cipher-base…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-08-20
date_modified: 2025-11-03
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-9287"
kev: false
cvss: 9.1
epss: 0.0055
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-9287: cipher-base is missing type checks, leading to hash rewind and passing on crafted data

**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?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.5% , percentile 45: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 45% 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 cipher-base (npm) <= 1.0.4, fixed in 1.0.5 . Check your lockfile, including transitive dependencies.

## What it is

Improper Input Validation vulnerability in cipher-base allows Input Data Manipulation.This issue affects cipher-base: through 1.0.4.

## Affected packages

- npm `cipher-base` <= 1.0.4 → fixed: 1.0.5

## Affected products (CVE record)

-  cipher-base: <= 1.0.4

## Severity

- harborist CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:N`
- GitHub CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.55% probability of exploitation activity in the next 30 days; percentile 45.

## Sources

- [github.com](https://github.com/browserify/cipher-base/security/advisories/GHSA-cpq7-6gpm-g9rc)
- [github.com](https://github.com/browserify/cipher-base/pull/23)
- [GitHub Advisory GHSA-cpq7-6gpm-g9rc](https://github.com/advisories/GHSA-cpq7-6gpm-g9rc)
- [CVE.org record CVE-2025-9287](https://www.cve.org/CVERecord?id=CVE-2025-9287)
- [NVD entry CVE-2025-9287](https://nvd.nist.gov/vuln/detail/CVE-2025-9287)
- [lists.debian.org](https://lists.debian.org/debian-lts-announce/2025/09/msg00005.html)
- [github.com](https://github.com/browserify/cipher-base/commit/8fd136432ca298a664f5637629cf2b42a6c7f294)

---
Source page: https://erroneo.us/security/cve/CVE-2025-9287/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt