---
id: CVE-2024-27306
aliases:
  - GHSA-7gpw-8wmc-pm8g
  - PYSEC-2026-1102
title: >-
  aiohttp Cross-site Scripting vulnerability on index pages for static file
  handling
summary: >-
  aiohttp Cross-site Scripting vulnerability on index pages for static file
  handling
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
vendor: aiohttp
product: aiohttp
ecosystem: pip
affected:
  - aiohttp < 3.9.4
patched:
  - aiohttp 3.9.4
published: '2024-04-18'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:11.218890208Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-7gpw-8wmc-pm8g'
references:
  - url: >-
      https://github.com/aio-libs/aiohttp/security/advisories/GHSA-7gpw-8wmc-pm8g
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-27306'
  - url: 'https://github.com/aio-libs/aiohttp/pull/8319'
  - url: 'https://github.com/aio-libs/aiohttp/pull/8319/files'
  - url: >-
      https://github.com/aio-libs/aiohttp/commit/28335525d1eac015a7e7584137678cbb6ff19397
  - url: 'https://github.com/aio-libs/aiohttp'
  - url: 'https://lists.debian.org/debian-lts-announce/2025/02/msg00002.html'
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2EXRGTN2WG7VZLUZ7WOXU5GQJKCPPHKP
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NWEI6NIHZ3G7DURDZVMRK7ZEFC2BTD3U
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZIVBMPEY7WWOFMC3CWXFBRQPFECV4SW3
tags:
  - osv
  - pip
epss: 0.00666
epssPercentile: 0.49647
ingestedAt: '2026-07-08T18:25:47.003Z'
---

## Overview

### 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 packages

- `aiohttp < 3.9.4`

## Remediation

Upgrade to a patched release:

- `aiohttp 3.9.4`