CVE-2025-6176
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedScrapy versions up to 2.13.2 are vulnerable to a denial of service (DoS) attack due to a flaw in its brotli decompression implementation. The protection mechanism against decompression bombs fails to mitigate the brotli variant, allowing remote servers to crash clients with less than 80GB of available memory. This occurs because brotli can achieve extremely high compression ratios for zero-filled data, leading to excessive memory consumption during decompression.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceScrapy up to version 2.13.2 contains a decompression bomb protection bypass in its brotli decompression implementation. While the framework implements safeguards againstzip-style decompression bombs, the brotli variant was not protected, allowing attackers to craft responses with extremely high compression ratios (especially on zero-filled data) that exhaust memory and crash the client with under 80GB available RAM.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Scrapy versionRun 'pip show scrapy' or 'python -c "import scrapy; print(scrapy.__version__)"' in your environmentAffected if The version is 2.13.2 or lower
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Verify brotli package is installedRun 'pip show brotli' or check if the brotli or brotlicffi package is present in your environmentAffected if The brotli package is installed and available to Scrapy
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Confirm brotli is not explicitly disabled in Scrapy settingsCheck your Scrapy settings file (settings.py) or Scrapy project configuration for the 'DOWNLOADER_CLIENT_BROTLI' or 'BROTLI_ENABLED' settingAffected if Brotli support is explicitly enabled or not explicitly set to False (defaults to enabled when package is present)
You are affected if Scrapy version is 2.13.2 or lower and the brotli package is installed with brotli support enabled in your configuration.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Scrapy to version 2.13.3 or later, which should include proper brotli decompression bomb protection. Until patched, consider disabling brotli compression support in Scrapy settings or implementing network-level filtering of excessively compressed responses.
Scrapy > 2.13.2 (e.g., 2.14.0 or later stable release)
- 1. Verify current Scrapy version by running: pip show scrapy | grep Version
- 2. Upgrade Scrapy to the latest stable release which contains the fix for the brotli decompression bomb vulnerability: pip install --upgrade scrapy
- 3. Alternatively, specify a version greater than 2.13.2: pip install scrapy>=2.14.0
- 4. Verify the upgrade was successful: pip show scrapy | grep Version
- 5. Test that your Scrapy projects still function correctly after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-6176 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-6176 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data