CVE-2026-34520

LOW EPSS 36.6%
Published Apr 1, 20263mo ago · Modified Jun 17, 20262w ago
2.7 CVSS 4.0
Low
Find Similar
Published Apr 1, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in response headers. This issue has been patched in version 3.13.4.

CVSS Details

Base Score
2.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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 Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
36.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-113

Affected Products 1

VendorProductVersionRange
aiohttpaiohttp* <3.13.4

References 3

  • github.com https://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4
    Patch
  • github.com https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
    Release Notes
  • github.com https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hf-3vf5-4wqf
    PatchVendor Advisory

Remediation

  • github.com https://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4
    Patch
  • github.com https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hf-3vf5-4wqf
    PatchVendor Advisory