Advisory Database
  • Advisories
  • Dependency Scanning
  1. pypi
  2. ›
  3. aiohttp
  4. ›
  5. CVE-2026-34525

CVE-2026-34525: AIOHTTP accepts duplicate Host headers

April 1, 2026

Multiple Host headers were allowed in aiohttp.

References

  • github.com/advisories/GHSA-c427-h43c-vf67
  • github.com/aio-libs/aiohttp
  • github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
  • github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
  • github.com/aio-libs/aiohttp/releases/tag/v3.13.4
  • github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67
  • nvd.nist.gov/vuln/detail/CVE-2026-34525

Code Behaviors & Features

Detect and mitigate CVE-2026-34525 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →

Affected versions

All versions before 3.13.4

Fixed versions

  • 3.13.4

Solution

Upgrade to version 3.13.4 or above.

Impact 5.4 MEDIUM

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

Learn more about CVSS

Weakness

  • CWE-20: Improper Input Validation
  • CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Source file

pypi/aiohttp/CVE-2026-34525.yml

Spotted a mistake? Edit the file on GitLab.

  • Site Repo
  • About GitLab
  • Terms
  • Privacy Statement
  • Contact

Page generated Sat, 09 May 2026 12:20:24 +0000.