CVE-2026-97689 urllib3 - Denial of Service

urllib3 1.10.3 to 2.8.0 contains a denial of service caused by unbounded memory allocation in HTTPResponse.read_chunked and HTTPResponse.stream due to unbounded chunk-size buffering, letting malicious servers exhaust client memory, exploit requires a malicious HTTP server.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.34% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
29 September 2026
Updated
15 October 2026
Weakness
CWE-770

Vendor fix

Update to version 2.8.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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