PT-2026-29610 · Aiohttp · Aiohttp

5Yu4N · Published 2026-04-01 · Updated 2026-05-18 · CVE-2026-34525

Positive Technologies (AI Summary)

CVSS v4.0

6.3

Medium

Base vector

AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N

Name of the Vulnerable Software and Affected Versions AIOHTTP versions prior to 3.13.4

Description Multiple Host headers were permitted in AIOHTTP, potentially allowing a reverse proxy's security rules to be bypassed. This could lead to a request being processed by AIOHTTP in a privileged sub application when using Application.add domain() if the proxy and AIOHTTP process different host names.

Recommendations Update to AIOHTTP version 3.13.4 or later.

Fix

RCE

HTTP Request/Response Smuggling

Weakness Enumeration

CWE-20

CWE-444

Related Identifiers

CLEANSTART-2026-AN27706

CVE-2026-34525

ECHO-F8CB-56CE-2D8E

GHSA-C427-H43C-VF67

OESA-2026-2192

OESA-2026-2193

OESA-2026-2194

Affected Products

Aiohttp

References · 63

• https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000 · Patch
• https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349 · Patch
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-34525 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-34514 · Security Note
• https://ubuntu.com/security/CVE-2026-34525 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-34525 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2026-2194 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-30922 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-34513 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-34073 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-44432 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-34052 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-34520 · Security Note
• https://osv.dev/vulnerability/CLEANSTART-2026-AN27706 · Vendor Advisory