CVE-2026-34518

AIOHTTP: Cookie and Proxy-Authorization headers leaked on cross-origin redirect

Published: Apr 1, 2026Updated: Apr 16, 2026 Sources: CVE List NVDCWE-200

5.3MEDIUM

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, when following redirects to a different origin, aiohttp drops the Authorization header, but retains the Cookie and Proxy-Authorization headers. This issue has been patched in version 3.13.4.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:LConfidentiality

Low

I:NIntegrity

None

A:NAvailability

None

Open in CVSS calculator →

Weaknesses

CWE-200 NVD-CWE-noinfo

Affected Products

aiohttp

oss-project

aiohttpLibrary

OSS Libraries / web-framework

aio-libs

oss-projectaka aiohttp, aiohttp session, aiosmtpd

aiohttpLibrary

OSS Libraries / web-framework

Exploitability

Official Patch Available

Is your org exposed to CVE-2026-34518?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique

Collection

View detailed technique mapping

References

https://github.com/aio-libs/aiohttp/commit/5351c980dcec7ad385730efdf4e1f4338b24fdb6

github.com

https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4

github.com

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-966j-vmvw-g2g9

github.com

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-34518 and every CVE in our database. Create a free account — no credit card required.

Create Free Account

Plain-language analysis

Impact assessment and exploitation scenario in plain English

Attack graph visualization

Interactive attack path and kill chain mapping

Exploit details & PoC links

ExploitDB, Metasploit, GitHub PoCs with direct links

Nuclei scanner templates

Ready-to-use vulnerability scanner templates

Full remediation guide

Patch instructions, workarounds, and compliance impact

Interactive AI chat

Ask questions about this vulnerability in natural language

Related vulnerabilities

Semantically similar CVEs and attack patterns

REST API & MCP access

Integrate vulnerability data into your workflows