Header Injection Vulnerability in AIOHTTP Framework by aio-libs
CVE-2026-50269

2.7LOW

Key Information:

Vendor

Aio-libs

Status
Aiohttp
Vendor
CVE Published:
22 June 2026

What is CVE-2026-50269?

AIOHTTP, the popular asynchronous HTTP client/server framework for Python, is susceptible to a header injection flaw prior to version 3.14.0. This vulnerability arises when attacker-controlled input in multipart/payload headers can alter a request by injecting additional headers. Specifically, if a user-controlled string is inadvertently utilized in MultipartWriter.append(headers=...) or Payload.headers, an attacker can manipulate the request's headers or contents. The issue has been addressed in version 3.14.0, ensuring applications utilizing the framework are secured against this risk.

Affected Version(s)

aiohttp < 3.14.0

References

https://github.com/aio-libs/aiohttp/security/advisories/G...
x_refsource_CONFIRM
https://github.com/aio-libs/aiohttp/commit/bf88077ebb14f4...
x_refsource_MISC

CVSS V4

Score:
2.7
Severity:
LOW
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.