CVE-2026-34525

MEDIUM EPSS 20.5%
Published Apr 1, 20263mo ago · Modified Jun 17, 20262w ago
6.3 CVSS 4.0
Medium
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, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

CVSS Details

Base Score
6.3
Exploitability
—
Impact
—
Vector string
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

Threat Intelligence

EPSS Exploit Probability
20.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-20 Improper Input Validation Validation
CWE-444

Affected Products 1

VendorProductVersionRange
aiohttpaiohttp* <3.13.4

References 4

  • github.com https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
    Patch
  • github.com https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
    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-c427-h43c-vf67
    PatchVendor Advisory

Remediation

  • github.com https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
    Patch
  • github.com https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
    Patch
  • github.com https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67
    PatchVendor Advisory