CVE-2025-6176Public exploitNetwork attack vector

Client crash via unbounded Brotli decompression

Published Oct 31, 2025 · Updated Oct 31, 2025

Denial of service in Scrapy 2.13.3 and earlier allows remote attackers to crash crawling clients through Brotli-compressed responses. HttpCompressionMiddleware limits compressed input rather than decompressed output, so a tiny zero-filled Brotli payload expands until memory is exhausted. A client must fetch an attacker-controlled response with Brotli support enabled; affected hosts with less than 80 GB of available memory can crash.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Scrapy 2.13.3 and earlier allows remote attackers to crash crawling clients through Brotli-compressed responses. HttpCompressionMiddleware limits compressed input rather than decompressed output, so a tiny zero-filled Brotli payload expands until memory is exhausted. A client must fetch an attacker-controlled response with Brotli support enabled; affected hosts with less than 80 GB of available memory can crash.

The record

CVE
CVE-2025-6176
Published
Oct 31, 2025
Updated
Oct 31, 2025
Vendor
Scrapy
Product
Scrapy
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 31, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 31, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=latest

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Scrapy · Scrapyversion=unspecified <=latest

Published CVSS scores

7.5GitHub Advisory DatabaseCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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