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Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input

High severity GitHub Reviewed Published Nov 8, 2025 in bugsink/bugsink • Updated Nov 13, 2025

Package

pip bugsink (pip)

Affected versions

< 2.0.5

Patched versions

2.0.5

Description

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

References

@vanschelven vanschelven published to bugsink/bugsink Nov 8, 2025
Published by the National Vulnerability Database Nov 10, 2025
Published to the GitHub Advisory Database Nov 13, 2025
Reviewed Nov 13, 2025
Last updated Nov 13, 2025

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(20th percentile)

Weaknesses

Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Learn more on MITRE.

CVE ID

CVE-2025-64508

GHSA ID

GHSA-fc2v-vcwj-269v

Source code

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