Skip to main content

Python CVE-2026-34525

| EUVDEUVD-2026-18048 MEDIUM
Improper Input Validation (CWE-20)
2026-04-01 GitHub_M GHSA-c427-h43c-vf67
Python Information Disclosure Red Hat Suse
6.3
CVSS 4.0 · GitHub Advisory
Share

Severity by source

GitHub Advisory PRIMARY
6.3 MEDIUM
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
SUSE
5.3 MEDIUM
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Red Hat
5.4 MEDIUM
qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

4
Patch released
Apr 02, 2026 - 02:30 nvd
Patch available
EUVD ID Assigned
Apr 01, 2026 - 21:00 euvd
EUVD-2026-18048
Analysis Generated
Apr 01, 2026 - 21:00 vuln.today
CVE Published
Apr 01, 2026 - 20:28 nvd
MEDIUM 6.3

Blast Radius

ecosystem impact
† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth
  • 122 pypi packages depend on aiohttp (43 direct, 79 indirect)

Ecosystem-wide dependent count for version 3.13.4.

DescriptionGitHub Advisory

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

AnalysisAI

AIOHTTP prior to version 3.13.4 allows multiple Host headers in HTTP requests, enabling information disclosure through header injection attacks. An unauthenticated remote attacker can exploit this by crafting malicious requests with duplicate Host headers to potentially bypass security controls or extract sensitive information from affected applications. The vulnerability has been patched in version 3.13.4, and no public exploit code or active exploitation has been identified at the time of analysis.

Technical ContextAI

AIOHTTP is a Python asynchronous HTTP client/server framework built on asyncio. The vulnerability stems from improper input validation (CWE-20) of HTTP headers during request processing. The root cause is that the framework failed to enforce single Host header requirements per RFC 7230, which specifies that HTTP requests should contain at most one Host header. When multiple Host headers are present, improper handling can lead to header confusion attacks where downstream systems parse different header values, potentially causing authentication bypasses, cache poisoning, or information disclosure. The affected component is the HTTP request parsing mechanism in aiohttp's core request handling code, as evidenced by commits addressing header validation logic.

RemediationAI

Upgrade AIOHTTP to version 3.13.4 or later, which includes the security patches from commits 53e2e6fc58b89c6185be7820bd2c9f40216b3000 and e00ca3cca92c465c7913c4beb763a72da9ed8349. For Python environments using pip, execute 'pip install --upgrade aiohttp>=3.13.4'. Validate the upgrade by verifying the installed version matches 3.13.4 or later. Organizations unable to upgrade immediately should implement input validation at the application or reverse proxy level to reject requests with multiple Host headers until patching is complete. Review deployment logs for evidence of suspicious requests with duplicate Host headers as part of post-patch verification.

More in Python

View all
CVE-2025-24016 CRITICAL POC
9.9 Feb 10

Wazuh SIEM platform versions 4.4.0 through 4.9.0 contain an unsafe deserialization vulnerability in the DistributedAPI t
CVE-2025-27520 CRITICAL POC
9.8 Apr 04

BentoML version 1.4.2 and earlier contains an unauthenticated remote code execution vulnerability through insecure deser
CVE-2025-2945 CRITICAL POC
9.9 Apr 03

pgAdmin 4 contains critical remote code execution vulnerabilities in the Query Tool download and Cloud Deployment endpoi
CVE-2013-5093 MEDIUM POC
6.8 Sep 27

The renderLocalView function in render/views.py in graphite-web in Graphite 0.9.5 through 0.9.10 uses the pickle Python

CVE-2025-32375 CRITICAL POC
9.8 Apr 09

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Rated critica
CVE-2014-0224 HIGH POC
7.4 Jun 05

OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h does not properly restrict processing of ChangeCiph
CVE-2024-21644 HIGH POC
7.5 Jan 08

pyLoad download manager version prior to 0.5.0b3.dev77 exposes the Flask SECRET_KEY through an unauthenticated endpoint.
CVE-2017-9462 HIGH POC
8.8 Jun 06

In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and conse
CVE-2026-39987 CRITICAL POC
9.3 Apr 08

Unauthenticated remote code execution in Marimo ≤0.20.4 allows attackers to execute arbitrary system commands via the `/
CVE-2024-21645 MEDIUM POC
5.3 Jan 08

pyLoad is the free and open-source Download Manager written in pure Python. Rated medium severity (CVSS 5.3), this vulne
CVE-2026-33017 CRITICAL POC
9.3 Mar 17

Langflow (a visual LLM pipeline builder) contains a critical unauthenticated code execution vulnerability (CVE-2026-3301
CVE-2026-55255 HIGH POC
8.4 Jun 19

Cross-user flow execution in Langflow (< 1.9.1) lets any authenticated API-key holder run another user's flow by passing

Same weakness CWE-20 – Improper Input Validation

View all
CVE-2021-44228 CRITICAL POC
10.0
CVE-2024-3400 CRITICAL POC
10.0
CVE-2022-47966 CRITICAL POC
9.8
CVE-2023-22515 CRITICAL POC
9.8
CVE-2009-0927 HIGH POC
8.8
CVE-2017-9791 CRITICAL POC
9.8
CVE-2017-15944 CRITICAL POC
9.8
CVE-2019-0604 CRITICAL POC
9.8

Same technique Information Disclosure

View all
CVE-2013-2251 CRITICAL POC
9.8
CVE-2017-5638 CRITICAL POC
9.8
CVE-2025-24813 CRITICAL POC
9.8
CVE-2015-1701 HIGH POC
7.8
CVE-2017-0147 HIGH POC
7.5
CVE-2014-6324 HIGH POC
8.8
CVE-2023-7028 CRITICAL POC
10.0
CVE-2017-0213 HIGH POC
7.3

Vendor StatusVendor

SUSE

Severity: Medium
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed
SUSE Linux Enterprise Module for Public Cloud 15 SP7 Fixed
SUSE Linux Enterprise Module for Python 3 15 SP7 Fixed
SUSE Linux Enterprise Server 15 SP7 Fixed

Share

CVE-2026-34525 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy