Denial of Service Vulnerability in aiohttp Framework by aio-libs
CVE-2026-128131

8.7HIGH

Key Information:

Vendor

Aio-libs

Status
Aiohttp
Vendor
CVE Published:
13 November 2026

What is CVE-2026-128131?

Prior to version 3.14.4, the aiohttp framework is susceptible to a denial of service condition due to its handling of multiple concatenated gzip, deflate, or zstd streams. The framework's design allows a remote attacker to craft a compressed request body that forces excessive CPU usage by decompressing members individually without imposing limits. This can lead to blocking the server's event loop or improperly managing client requests, making it critical for users to upgrade to version 3.14.4 to mitigate the issue.

Affected Version(s)

aiohttp < 3.14.4

References

https://github.com/aio-libs/aiohttp/security/advisories/G...
x_refsource_CONFIRM
https://github.com/aio-libs/aiohttp/pull/13362
x_refsource_MISC
https://github.com/aio-libs/aiohttp/pull/13391
x_refsource_MISC

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.