CVE-2026-44432
urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API
No known exploitation. EPSS puts it in the 57th percentile. Only a workaround so far.
What to do
No fixed build is published yet. The vendor describes a workaround.
What it is
From the CVE record
urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was called after the response had been read and decompressed partially (compression algorithm did not matter here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This could result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.9% chance of exploitation activity in the next 30 days, which ranks it in the 57th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
43 events over 120 days, from the signal feeds we watch.
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Scored 7.5 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
References in the record
- github.com/urllib3/urllib3/security/advisories/GHSA-mf9v-mfxr-j63j
- access.redhat.com/errata/RHSA-2026:15862
- access.redhat.com/errata/RHSA-2026:20338
And 59 more references. See all after sign-in
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