PkgSeer

Vulnerability PYSEC-2026-1350

Unknown
UNKNOWN RISK
Vulnerabilities without an assigned CVSS score. Severity is not determinable from available data.
4 months ago
July 07, 2026 at 04:03 PM UTC
Eventlet affected by HTTP request smuggling in unparsed trailers
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.40.2
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.40.2

Summary

Eventlet affected by HTTP request smuggling in unparsed trailers

Details

Impact

The Eventlet WSGI parser is vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer sections.

This vulnerability could enable attackers to:

  • Bypass front-end security controls
  • Launch targeted attacks against active site users
  • Poison web caches

Patches

Problem has been patched in eventlet 0.40.3.

The patch just drops trailers. If a backend behind eventlet.wsgi proxy requires trailers, then this patch BREAKS your setup.

Workarounds

Do not use eventlet.wsgi facing untrusted clients.

References

Related Vulnerabilities

Other vulnerabilities affecting the same packages

Medium Risk
4 months ago
Potential DoS via the Tudoor mechanism in eventlet and dnspython
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.35.1 PYSEC-2026-2472
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.35.1 PYSEC-2026-2472
Medium Risk
1 year ago
Eventlet affected by HTTP request smuggling in unparsed trailers
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.40.2 GHSA-hw6f-rjfj-j7j7
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.40.2 GHSA-hw6f-rjfj-j7j7
Medium Risk
2 years ago
Potential DoS via the Tudoor mechanism in eventlet and dnspython
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.35.1 GHSA-3rq5-2g8h-59hc
0.2 and 0.5.3 and 0.6.1 and 0.7 and 0.8 and 0.8.16 and 0.9.17 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.33.3 and 0.34.1 - 0.35.1 GHSA-3rq5-2g8h-59hc
Medium Risk
5 years ago
Improper Handling of Highly Compressed Data (Data Amplification) and Memory Allocation with Excessive Size Value in eventlet
0.10.0 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.30.3 GHSA-9p9m-jm8w-94p2
0.10.0 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.30.3 GHSA-9p9m-jm8w-94p2
Unknown
5 years ago
No summary available
0.10.0 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.30.3 PYSEC-2021-12
0.10.0 - 0.11.0 and 0.12.1 - 0.14.0 and 0.15.2 and 0.16.1 and 0.17.4 and 0.18.2 - 0.30.3 PYSEC-2021-12
View all vulnerabilities for these packages

Impacted packages

Timeline

Published
4 months ago
July 07, 2026 at 04:03 PM UTC
Fixed (0.40.3)
1 year ago
August 27, 2025 at 09:56 AM UTC
Last Modified
4 months ago
July 07, 2026 at 05:46 PM UTC