Vulnerability in Httplib2

CVE-2026-59939

httplib2 is a comprehensive HTTP client library for Python. Prior to 0.32.0, httplib2 performs unbounded decompression of HTTP response bodies encoded with Content-Encoding: gzip or deflate in _decompressContent in httplib2/init.py, allowing a malicious or compromised HTTP server to return a small compressed payload that expands to an arbitrarily large size in memory and causes MemoryError or OOM-kill in the client process. This issue is fixed in version 0.32.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (50.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-59939: held from 0.004 to 0.007.

EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-59939?
CVE-2026-59939 is a high-severity vulnerability in Httplib2, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-07-08.
How severe is CVE-2026-59939?
High severity. CVSS v3 base score is 7.5 out of 10.