CVE-2026-59939: httplib2 — Exploit & Fix

Description

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.

Is your site exposed to CVE-2026-59939?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0036

Probability of exploitation

0.28%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-409 CWE-409

Affected Products

Vendor	Product	Versions
httplib2_project	httplib2	< 0.32.0

References

Advisories & Patches

https://github.com/httplib2/httplib2/commit/87581ad6cf752fe3da2090c59058261d2d00a427 https://github.com/httplib2/httplib2/security/advisories/GHSA-j5g9-f88f-gfj3 https://github.com/httplib2/httplib2/security/advisories/GHSA-j5g9-f88f-gfj3

Exploits

https://github.com/httplib2/httplib2/security/advisories/GHSA-j5g9-f88f-gfj3 https://github.com/httplib2/httplib2/security/advisories/GHSA-j5g9-f88f-gfj3

Other References

https://github.com/httplib2/httplib2/releases/tag/v0.32.0

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-59939? +

CVE-2026-59939 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0036, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-59939? +

CVE-2026-59939 affects products from httplib2_project, specifically: httplib2. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-59939? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-66019

pypdf is a free and open-source pure-python PDF library. Prior to version 6.4.0, an attacker who uses this vulnerability can …

CVE-2026-48594

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-tesla tesla allows a denial of service via decompression bomb …

CVE-2026-62963

Centrifugo is an open-source scalable real-time messaging server. Prior to 6.8.4, Centrifugo unidirectional WebSocket transport with uni_websocket.compression enabled enforced uni_websocket.message_size_limit …

CVE-2026-49755

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in wojtekmach Req allows attacker-controlled HTTP servers to exhaust memory in …

CVE-2026-12588

An attacker with access to an HX 10.0.0 and previous versions, may send specially-crafted data to the HX console. The …

CVE-2026-53430

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-grpc grpc (GRPC.Compressor.Gzip, GRPC.Message modules) allows a denial of service …

CVE-2026-59939