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

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 ...

EUVD-2026-38323

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-2026-53538 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

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: 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-2026-50559

Quarkus is a Java framework for building cloud-native applications. Prior to versions 3.37.0, 3.36.3, 3.33.2.1, 3.33.3, 3.27.4.1, 3.27.5, and 3.20.6.2, Quarkus HTTP path-based authorization policies can be bypassed using encoded semicolons %3B to smuggle matrix parameters past the security layer,...

python-multipart: Quadratic-time querystring parsing with semicolon separators causes CPU denial of service

Summary 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 did it fall back to scanning for ;. For a body that uses ; as the...

GHSA-5RVQ-CXJ2-64VF python-multipart: Quadratic-time querystring parsing with semicolon separators causes CPU denial of service

Summary 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 did it fall back to scanning for ;. For a body that uses ; as the...

Inefficient Algorithmic Complexity

Overview python-multipart is an A streaming multipart parser for Python Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the QuerystringParser function when parsing application/x-www-form-urlencoded bodies containing semicolon-separated fields. An attacker...

python-multipart: Semicolon treated as querystring field separator enables parameter smuggling

Summary 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 & as a separator. This creates a parser differential: the same bytes...

PT-2026-49571

Name of the Vulnerable Software and Affected Versions python-multipart versions prior to 0.0.30 Description A quadratic complexity issue exists when parsing application/x-www-form-urlencoded bodies. The QuerystringParser performs a two-step lookup for field separators, scanning the entire remaini...

PT-2026-49570

Name of the Vulnerable Software and Affected Versions Python-Multipart versions prior to 0.0.30 Description The QuerystringParser treated the semicolon ; as a field separator in application/x-www-form-urlencoded bodies, in addition to the ampersand &. This deviates from the WHATWG URL standard,...

EUVD-2026-35417

A flaw was found in 389 Directory Server. The LDIF parser reads past the end of a heap buffer when processing attribute types with trailing semicolons during database import, causing an out-of-bounds read detectable under memory instrumentation...

CVE-2026-33808

Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via duplicate slashes when ignoreDuplicateSlashes is enabled, or...