---
id: CVE-2025-64508
aliases:
  - GHSA-fc2v-vcwj-269v
  - PYSEC-2026-1225
title: Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input
summary: Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: bugsink
product: bugsink
ecosystem: pip
affected:
  - bugsink < 2.0.5
patched:
  - bugsink 2.0.5
published: '2025-11-13'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-fc2v-vcwj-269v'
references:
  - url: 'https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-64508'
  - url: 'https://github.com/google/brotli/issues/1327'
  - url: 'https://github.com/google/brotli/issues/1375'
  - url: 'https://github.com/bugsink/bugsink/pull/266'
  - url: 'https://github.com/google/brotli/pull/1234'
  - url: >-
      https://github.com/bugsink/bugsink/commit/3f65544aab3ad5303d97009136640de97b0676a5
  - url: >-
      https://github.com/google/brotli/commit/67d78bc41db1a0d03f2e763497748f2f69946627
  - url: 'https://github.com/bugsink/bugsink'
  - url: 'https://github.com/google/brotli/releases/tag/v1.2.0'
tags:
  - osv
  - pip
epss: 0.00472
epssPercentile: 0.38115
ingestedAt: '2026-07-08T18:25:48.857Z'
---

## Overview

### Impact

In affected versions, brotli "bombs" (highly compressed brotli streams, such as many zeros) can be sent to the server. Since the server will attempt to decompress these streams before applying various maximums, this can lead to exhaustion of the available memory and thus a Denial of Service.

This can be done if the `DSN` is known, which it is in many common setups (JavaScript, Mobile Apps).

### Patches

Patched in Bugsink `2.0.5`

## Affected packages

- `bugsink < 2.0.5`

## Remediation

Upgrade to a patched release:

- `bugsink 2.0.5`