CVE-2025-6176 | Brotli decompression bomb DoS in scrapy/scrapy

Scrapy 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.

Published: 2025-10-31 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-6176 is rated Moderate Risk (43.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.47%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-6176

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.47% +0.43%
2 2026-03-29 0.05% 0.03% -0.02%
3 2026-03-04 — 0.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6176

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-6176

GitHub Security Advisory for CVE-2025-6176

GHSA-2qfp-q593-8484 · Severity: high · Ecosystem: pip — Scrapy is vulnerable to a denial of service (DoS) attack due to flaws in brotli decompression implementation

OS Trackers for CVE-2025-6176

vendor priority summary link
debian unimportant CVE-2025-6176 unimportant priority: Debian including 1 source packages (python-scrapy), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2025-6176
redhat high — https://access.redhat.com/security/cve/CVE-2025-6176
suse high CVE-2025-6176 severity important: SUSE including 21 source package names (brotli-1.0.6-4.el8_10, brotli-1.0.9-9.el9_7, …), 21 product×package rows across 4 product lines (SUSE Liberty Linux 10, SUSE Liberty Linux 8, SUSE Liberty Linux 9, openSUSE Tumbleweed): Fixed 21. https://www.suse.com/security/cve/CVE-2025-6176/
ubuntu medium CVE-2025-6176 medium priority: Ubuntu including 1 source packages (python-scrapy), 8 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, upstream, xenial): needs-triage 7, ignored 1. https://ubuntu.com/security/CVE-2025-6176

Affected software / configurations for CVE-2025-6176

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-6176

cvelogic Threat Intelligence