CVE-2026-47265
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.
02 / AFFECTED SOFTWARE
Affected packages
306 explicit affected versions
306 explicit affected versions
148 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.
### Summary Cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. ### Impact If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. ### Workaround If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable. ----- Patch: https://github.com/aio-libs/aiohttp/commit/f54c40851b0d6c4bbdab97ba518a223adda32478
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47265.json
- https://github.com/aio-libs/aiohttp/commit/f54c40851b0d6c4bbdab97ba518a223adda32478
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hg6j-4rv6-33pg
- https://nvd.nist.gov/vuln/detail/CVE-2026-47265
- https://github.com/aio-libs/aiohttp