← Vulnerability feed

Vulnerability record · CVE-2026-54277 · published 22 June 2026

CVE-2026-54277: Aiohttp allocation without limits vulnerability

Aiohttp · Aiohttp

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.

6.6 CVSS 4.0 Medium EPSS 0.56% · top 55.4% CWE-770 · Allocation without limits
6.6CVSS 4.0 base score
0.56%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
30 Jun 2026Last modified by NVD

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d Patch
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2 Vendor Advisory

Track CVE-2026-54277 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.7CVE-2024-52303Aiohttp vulnerabilityaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. In versions starting with 3.10.6 and prior to 3.10.11, a memory leak …EPSS 0.59%7.5CVE-2025-69223Aiohttp allocation without limits vulnerabilityAIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below allow a zip bomb to be used to execute a Do…EPSS 0.57%7.5CVE-2024-30251Aiohttp vulnerabilityaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. In affected versions an attacker can send a specially crafted POST (m…EPSS 1.1%7.5CVE-2024-23334aiohttp static route path traversal when follow_symlinks is enabledaiohttp, an asynchronous HTTP client/server framework for Python, fails to validate that files read through static routes remain inside the configure…EPSS 77%analysed7.5CVE-2023-47627Aiohttp http request smuggling vulnerabilityaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing,…EPSS 0.86%7.5CVE-2023-37276Aiohttp http request smuggling vulnerabilityaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. aiohttp v3.8.4 and earlier are bundled with llhttp v6.0.6. Vulnerable…EPSS 1.3%7.3CVE-2026-34993Aiohttp deserialization of untrusted data vulnerabilityAIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, using ``CookieJar.load()`` with untrusted in…EPSS 0.50%6.9CVE-2026-22815Aiohttp uncontrolled resource consumption vulnerabilityAIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, insufficient restrictions in header/trailer …EPSS 0.44%

Source: NIST National Vulnerability Database (record CVE-2026-54277), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.