CVE-2026-34519 — MEDIUM (5.3)

Q: How severe is CVE-2026-34519?

CVE-2026-34519 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-34519?

Check the references section above for vendor advisories and patch information. Affected products include: Aiohttp Aiohttp.

Vulnerability Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Aiohttp	Aiohttp	< 3.13.4

Related Weaknesses (CWE)

CWE-113

References

https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642bPatch
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4Release Notes
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mwh4-6h8g-pg8wPatchVendor Advisory

FAQ

What is CVE-2026-34519?

CVE-2026-34519 is a vulnerability with a CVSS score of 5.3 (MEDIUM). AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject ex...

How severe is CVE-2026-34519?

CVE-2026-34519 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-34519?

Check the references section above for vendor advisories and patch information. Affected products include: Aiohttp Aiohttp.