# CVE-2026-47265: AIOHTTP sensitive cookie leak during cross-origin redirect

Source: https://junglewise.ai/threats/cve-2026-47265-aiohttp-sensitive-cookie-leak-during-cross-origin-redirect  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-02. Updated: 2026-06-03  
License: CC BY 4.0 with a link back

CVE-2026-47265 · Severity: medium · CVSS 4 · Published 2026-06-02

AIOHTTP is a popular Python library used by developers to build web servers and clients. A security flaw in the library's client component causes sensitive session cookies to be sent to unintended third-party websites during a redirect. If an attacker can trick an application into following a redirect to a malicious server, they could steal authentication tokens or other private user data.

Technologies: [aiohttp (PyPI)](https://junglewise.ai/threats/technologies/aiohttp). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-47265 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47265 being exploited in the wild.

**How severe is CVE-2026-47265?** Medium severity, with a CVSS score of 4, published 2 June 2026.

**Which products and versions are affected?** aiohttp (PyPI) < 3.14.0, ECOSYSTEM:introduced=0,fixed=3.14.0.

**Is there a fix for CVE-2026-47265?** Yes. aiohttp (PyPI): upgrade to 3.14.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47265 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47265?** Check whether you run aiohttp (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- aiohttp (PyPI): upgrade to 3.14.0 or later

  ```sh
  pip install "aiohttp>=3.14.0"
  ```


## Technical details

AIOHTTP fails to properly validate the origin before forwarding cookies during an HTTP redirect. When a request is initiated using the 'cookies' parameter, the library persists these cookies even if the server responds with a redirect to a different domain (cross-origin). An attacker who can control the destination of a redirect can capture these cookies, which may contain sensitive session identifiers or authentication tokens. This issue is rooted in the client-side request handling logic within 'aiohttp/client.py'. The vulnerability is addressed in version 3.14.0 by ensuring per-request cookies are dropped upon cross-origin redirection.

## Affected products

- aio-libs aiohttp < 3.14.0

## Identifiers

- CVE-2026-47265
- GHSA-hg6j-4rv6-33pg
- PYSEC-2026-2105

## Timeline

- 2026-06-02: disclosed
- 2026-06-02: patched
- 2026-06-03: advisory

## References

- [https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hg6j-4rv6-33pg](https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hg6j-4rv6-33pg)
- [https://github.com/aio-libs/aiohttp/commit/f54c40851b0d6c4bbdab97ba518a223adda32478](https://github.com/aio-libs/aiohttp/commit/f54c40851b0d6c4bbdab97ba518a223adda32478)
- [https://api.github.com/repos/aio-libs/aiohttp/security-advisories/GHSA-hg6j-4rv6-33pg](https://api.github.com/repos/aio-libs/aiohttp/security-advisories/GHSA-hg6j-4rv6-33pg)

## Related threats

- [aiohttp HTTP request smuggling in pure Python parser](https://junglewise.ai/threats/cve-2026-111750-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp host-only cookie scope bypass in subdomain handling](https://junglewise.ai/threats/cve-2026-111749-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp Request scheme manipulation in absolute-form requests](https://junglewise.ai/threats/cve-2026-111748-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [AIOHTTP multipart request file descriptor exhaustion](https://junglewise.ai/threats/cve-2026-111066-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp cookie Max-Age integer overflow causes connection pool exhaustion](https://junglewise.ai/threats/cve-2026-111065-aiohttp-is-an-asynchronous-http-client-server-framework-for)