Medium

aiohttp Cross-site Scripting vulnerability on index pages for static file handling

  • Disclosed: 18.04.2024
  • Updated: 11.10.2026 15:17

Summary

A XSS vulnerability exists on index pages for static file handling.

Details

When using web.static(..., show_index=True), the resulting index pages do not escape file names.

If users can upload files with arbitrary filenames to the static directory, the server is vulnerable to XSS attacks.

Workaround

We have always recommended using a reverse proxy server (e.g. nginx) for serving static files. Users following the recommendation are unaffected.

Other users can disable show_index if unable to upgrade.


Patch: https://github.com/aio-libs/aiohttp/pull/8319/files

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) aiohttp < 3.9.4 3.9.4

References

CVSS score 6.1/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79
Platform
Python (PyPI)
Package
aiohttp
Disclosed
18.04.2024
Updated
11.10.2026 15:17

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-1102 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-7gpw-8wmc-pm8g - CC BY 4.0

Vulnerability history: aiohttp

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (55) in the archive
Total entries
55
First → latest
02.2021 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 7
  • Medium 29
  • Low 19

Disclosures per year

  1. 2021: 1
  2. 2022: 0
  3. 2023: 6
  4. 2024: 7
  5. 2025: 1
  6. 2026: 40
Severity:
  1. High CVE-2026-111066 >= 2.0.0, < 3.14.4 3.14.4
  2. High CVE-2026-111064 < 3.14.4 3.14.4
  3. aiohttp Cross-site Scripting vulnerability on index pages for static file handling this entry
    Medium · 6.1 CVE-2024-27306 < 3.9.4 3.9.4
  4. High · 5.9 CVE-2024-23334 >= 1.0.5, < 3.9.2 3.9.2

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