PT-2026-29610 · Aiohttp+1 · Aiohttp+1

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CVE-2026-34525

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Published

2026-03-15

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Updated

2026-08-21

CVSS v4.0

6.9

Medium

VectorAV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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.

Exploit

Fix

DoS

RCE

HTTP Request/Response Smuggling

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Weakness Enumeration

Related Identifiers

AZL-81782
BDU:2026-09579
CLEANSTART-2026-AN24336
CLEANSTART-2026-AN27706
CLEANSTART-2026-AZ09261
CLEANSTART-2026-CQ05396
CLEANSTART-2026-EM82280
CLEANSTART-2026-FU07345
CLEANSTART-2026-HP19968
CLEANSTART-2026-IR98353
CLEANSTART-2026-KE11953
CLEANSTART-2026-MR94452
CLEANSTART-2026-NL78203
CLEANSTART-2026-NM83456
CLEANSTART-2026-QE89118
CLEANSTART-2026-SO50412
CLEANSTART-2026-WQ85001
CLEANSTART-2026-WU03167
CVE-2026-34525
ECHO-F8CB-56CE-2D8E
GHSA-C427-H43C-VF67
OESA-2026-2192
OESA-2026-2193
OESA-2026-2194
OPENSUSE-SU-2026:21098-1
PYSEC-2026-2103
SUSE-SU-2026:22173-1
SUSE-SU-2026:3059-1
SUSE-SU-2026:3207-1

Affected Products

Aiohttp
Red Os