CVE-2024-27306 | aiohttp vulnerable to XSS on index pages for static file handling

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. A XSS vulnerability exists on index pages for static file handling. This vulnerability is fixed in 3.9.4. 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.

Published: 2024-04-18 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-27306 is rated Moderate Risk (49.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.71%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-27306

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 0.59% 0.71% +0.12%
2 2026-05-23 0.71% 0.59% -0.12%
3 2026-04-25 — 0.71% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-27306

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]

Weakness enumeration for CVE-2024-27306

GitHub Security Advisory for CVE-2024-27306

GHSA-7gpw-8wmc-pm8g · Severity: medium · Ecosystem: pip — aiohttp Cross-site Scripting vulnerability on index pages for static file handling

OS Trackers for CVE-2024-27306

vendor priority summary link
debian not yet assigned CVE-2024-27306 not yet assigned priority: Debian including 1 source packages (python-aiohttp), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2024-27306
redhat medium — https://access.redhat.com/security/cve/CVE-2024-27306
suse medium — https://www.suse.com/security/cve/CVE-2024-27306/
ubuntu medium CVE-2024-27306 medium priority: Ubuntu including 1 source packages (python-aiohttp), 10 status rows across 10 suites (bionic, focal, jammy, mantic, noble, oracular, plucky, questing, upstream, xenial): released 5, not-affected 4, ignored 1. https://ubuntu.com/security/CVE-2024-27306

Affected software / configurations for CVE-2024-27306

Vendor Product Version Raw CPE
aiohttp aiohttp < 3.9.4 cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
fedoraproject fedora 40 cpe:2.3:o:fedoraproject:fedora:40:*:*:*:*:*:*:*

References for CVE-2024-27306

cvelogic Threat Intelligence