SUSE SLES15 Security Update : python-aiohttp (SUSE-SU-2026:3059-1)

The remote SUSE Linux SLES15 / SLESSAP15 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3059-1 advisory. This update for python-aiohttp fixes the following issues - CVE-2026-22815: insufficient header/trailer handling can cause a denial...

PYSEC-2026-3033 python-engineio has possible denial of service due to maximum payload size sometimes not being enforced

Impact There are two specific configurations of the python-engineio server in which the size of incoming messages is not checked before the messages are loaded into memory. An attacker can take advantage of these to cause unnecessary memory allocations in the python-engineio server. The two cases...

The vulnerability of the aiohttp HTTP client, related to the failure to handle CRLF sequences in HTTP headers, allows attackers to inject arbitrary HTTP headers.

The vulnerability of the aiohttp HTTP client is related to the failure to handle CRLF sequences in HTTP headers when processing the reason parameter. Exploiting this vulnerability allows an attacker who operates remotely to inject arbitrary HTTP headers...

PYSEC-2026-1106 AIOHTTP vulnerable to DoS through chunked messages

Summary Handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. Impact If an application makes use of the request.read method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU...

PYSEC-2026-1100 AIOHTTP vulnerable to denial of service through large payloads

Summary A request can be crafted in such a way that an aiohttp server's memory fills up uncontrollably during processing. Impact If an application includes a handler that uses the Request.post method, an attacker may be able to freeze the server by exhausting the memory. ----- Patch:...

PYSEC-2026-1105 AIOHTTP Vulnerable to Cookie Parser Warning Storm

Summary Reading multiple invalid cookies can lead to a logging storm. Impact If the cookies attribute is accessed in an application, then an attacker may be able to trigger a storm of warning-level logs using a specially crafted Cookie header. ---- Patch:...

PYSEC-2026-1107 AIOHTTP vulnerable to DoS when bypassing asserts

Summary When assert statements are bypassed, an infinite loop can occur, resulting in a DoS attack when processing a POST body. Impact If optimisations are enabled -O or PYTHONOPTIMIZE=1, and the application includes a handler that uses the Request.post method, then an attacker may be able to...

PYSEC-2026-1097 AIOHTTP vulnerable to brute-force leak of internal static file path components

Summary Path normalization for static files prevents path traversal, but opens up the ability for an attacker to ascertain the existence of absolute path components. Impact If an application uses web.static not recommended for production deployments, it may be possible for an attacker to ascertai...

PYSEC-2026-1109 AIOHTTP has unicode match groups in regexes for ASCII protocol elements

Summary The parser allows non-ASCII decimals to be present in the Range header. Impact There is no known impact, but there is the possibility that there's a method to exploit a request smuggling vulnerability. ---- Patch:...

PYSEC-2026-1099 AIOHTTP's unicode processing of header values could cause parsing discrepancies

Summary The Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. Impact If a pure Python version of aiohttp is installed i.e. without the usual C extensions or AIOHTTPNOEXTENSIONS is enabled, then an attacker may be able to execute a request smuggling...

PYSEC-2026-1101 AIOHTTP's HTTP Parser auto_decompress feature is vulnerable to zip bomb

Summary A zip bomb can be used to execute a DoS against the aiohttp server. Impact An attacker may be able to send a compressed request that when decompressed by aiohttp could exhaust the host's memory. ------ Patch: https://github.com/aio-libs/aiohttp/commit/2b920c39002cee0ec5b402581779bbaaf7c91...

PYSEC-2026-1452 Home Assistant does not correctly validate SSL for outgoing requests in core and used libs

Summary Problem: Potential man-in-the-middle attacks due to missing SSL certificate verification in the project codebase and used third-party libraries. Details In the past, aiohttp-session/request had the parameter verifyssl to control SSL certificate verification. This was a boolean value. In...

PYSEC-2026-1096 aiohttp has a memory leak when middleware is enabled when requesting a resource with a non-allowed method

Summary A memory leak can occur when a request produces a MatchInfoError. This was caused by adding an entry to a cache on each request, due to the building of each MatchInfoError producing a unique cache entry. Impact If the user is making use of any middlewares with aiohttp.web then it is...

PYSEC-2026-1103 aiohttp allows request smuggling due to incorrect parsing of chunk extensions

Summary The Python parser parses newlines in chunk extensions incorrectly which can lead to request smuggling vulnerabilities under certain conditions. Impact If a pure Python version of aiohttp is installed i.e. without the usual C extensions or AIOHTTPNOEXTENSIONS is enabled, then an attacker m...

PYSEC-2026-1108 In aiohttp, compressed files as symlinks are not protected from path traversal

Summary Static routes which contain files with compressed variants .gz or .br extension were vulnerable to path traversal outside the root directory if those variants are symbolic links. Details The server protects static routes from path traversal outside the root directory when...

PYSEC-2026-1098 aiohttp vulnerable to Denial of Service when trying to parse malformed POST requests

Summary An attacker can send a specially crafted POST multipart/form-data request. When the aiohttp server processes it, the server will enter an infinite loop and be unable to process any further requests. Impact An attacker can stop the application from serving requests after sending a single...

Python Library aiohttp < 3.14.1 Multiple Vulnerabilities

The version of the aiohttp Python library installed on the remote host is prior to 3.14.1. It is, therefore, affected by multiple vulnerabilities: - Prior to 3.14.1, no limit was present on the number of pipelined requests that could be queued. An attacker may be able to use pipelined requests to...

Python Library aiohttp < 3.14.0 Header Injection

The version of the aiohttp Python library installed on the remote host is prior to 3.14.0. It is, therefore, affected by a vulnerability: - Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. I...

CVE-2026-50269

A flaw was found in aiohttp, an asynchronous HTTP client/server framework. This vulnerability, known as CRLF Carriage Return Line Feed injection, allows an attacker to modify HTTP requests by injecting malicious input into multipart or payload headers. If an application processes user-controlled...

GHSA-M9GH-VJ53-GVH9 python-engineio has possible denial of service due to maximum payload size sometimes not being enforced

Impact There are two specific configurations of the python-engineio server in which the size of incoming messages is not checked before the messages are loaded into memory. An attacker can take advantage of these to cause unnecessary memory allocations in the python-engineio server. The two cases...