CVE-2026-53537

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, parseoptionsheader parsed Content-Disposition and Content-Type headers with email.message.Message, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax filename=charset'lang'value, name=...,...

CVE-2026-53537 Python-Multipart: Content-Disposition parameter smuggling via RFC 2231/5987 extended parameters

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, parseoptionsheader parsed Content-Disposition and Content-Type headers with email.message.Message, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax filename=charset'lang'value, name=...,...

CVE-2026-53537

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, parseoptionsheader parsed Content-Disposition and Content-Type headers with email.message.Message, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax filename=charset'lang'value, name=...,...

CVE-2026-53537 Python-Multipart: Content-Disposition parameter smuggling via RFC 2231/5987 extended parameters

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, parseoptionsheader parsed Content-Disposition and Content-Type headers with email.message.Message, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax filename=charset'lang'value, name=...,...

CVE-2026-53537

Python-Multipart: Prior to 0.0.30, parse_options_header could decode RFC 2231/5987 extended parameters (filename*=, name*=, etc.) via email.message, leading to the filename/field name being surfaced in ways that RFC 7578 forbids. This allowed parameter smuggling where an attacker could bypass ups...

CVE-2026-53538

CVE-2026-53538 affects python-multipart, a streaming multipart parser for Python. Prior to 0.0.30, the QuerystringParser treated ";" as a field separator in application/x-www-form-urlencoded bodies in addition to "&", creating a parsing differential against WHATWG/urllib.parse behavior that only ...

CVE-2026-53538

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse since the CVE-2021-23336 fix treat only...

CVE-2026-53538 Python-Multipart: Semicolon treated as querystring field separator enables parameter smuggling

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse since the CVE-2021-23336 fix treat only...

CVE-2026-53538

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse since the CVE-2021-23336 fix treat only...

CVE-2026-53538 Python-Multipart: Semicolon treated as querystring field separator enables parameter smuggling

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse since the CVE-2021-23336 fix treat only...

CVE-2026-53539 Python-Multipart: Quadratic-time querystring parsing with semicolon separators causes CPU denial of service

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead...

CVE-2026-53539

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead...

CVE-2026-53539 Python-Multipart: Quadratic-time querystring parsing with semicolon separators causes CPU denial of service

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead...

CVE-2026-53539

CVE-2026-53539 (Python-Multipart) affects the Python-Multipart streaming multipart parser. Prior to 0.0.30, parsing application/x-www-form-urlencoded bodies used a two-step field separator lookup, causing an O(B^2) worst-case workload per chunk when semicolon is used as the separator and no amper...

CVE-2026-53539

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead...

CVE-2026-54280 AIOHTTP: Payload Response Resources Are Not Closed After Mid-Body Disconnect

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, payload resources are not closed correctly when a client disconnects in the middle of a write. If a payload is using an open file or similar limited resource, then an attacker may be able to cause...

CVE-2026-50269 AIOHTTP: CRLF injection in multipart headers

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. 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. In the unlikely situation that an application is passing...

urllib3: urllib3: Denial of Service due to excessive HTTP response decompression

A flaw was found in urllib3, an HTTP client library for Python. This vulnerability allows a remote attacker to cause excessive resource consumption, such as high CPU usage and massive memory allocation, on the client side. This occurs when urllib3 attempts to decompress an entire HTTP response,...

Important: Red Hat Security Advisory: python3.14-urllib3 security update

An update for python3.14-urllib3 is now available for Red Hat Enterprise Linux 10. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is available for each...

urllib3: urllib3: Information disclosure via cross-origin redirects forwarding sensitive headers

A flaw was found in urllib3, an HTTP client library for Python. When using the low-level API via ProxyManager.connectionfromurl.urlopen with assertsamehost=False, cross-origin redirects can still forward sensitive headers. This could allow a remote attacker to gain unauthorized access to sensitiv...