PYSEC-2026-3036 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...

PYSEC-2026-3025 pypdf: Manipulated XMP metadata streams can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing large XMP metadata, possibly with lots of unnecessary elements. Patches This has been fixed in pypdf==6.12.1. Workarounds If you cannot upgrade yet, consider applying the change...

PYSEC-2026-3037 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...

PYSEC-2026-2862 PDM: Project-Local State and Config Writes Follow Symlinks

Summary PDM writes several project-local state or configuration files without symlink protection. If a malicious repository places those files as symlinks, local PDM operations can overwrite the symlink targets. This creates an arbitrary file clobber primitive relative to the privileges of the...

PYSEC-2026-3435 python-zeroconf: Unbounded TC-deferred queue allows LAN-local memory exhaustion via spoofed-source flood

Impact AsyncListener.handlequeryordefer retained every truncated TC-bit incoming query in self.deferredaddr and armed a per-addr timer in self.timersaddr that flushed the reassembled query within 500 ms RFC 6762 §18.5. Neither the per-addr list nor the number of distinct addr keys was capped, and...

PYSEC-2026-2971 rattler has an entry-point path traversal in noarch:python install (arbitrary file write)

Summary EntryPoint::FromStr in rattlercondatypes performs only .trim on the command field before the linker joins it onto the install prefix and writes an executable Python script. A malicious noarch:python package can ship an info/link.json with an entry-point name containing .., /, , or an...

PYSEC-2026-2916 PraisonAI has an Arbitrary File Write in Python API

Bug Report: Arbitrary File Write in Python API Summary Hidden metadata in a webpage causes PraisonAI agents to write attacker-controlled content to arbitrary paths. writefile skips path validation when workspace=None always None in production. Affected PraisonAI outputfile: /tmp/flag.txt...

PYSEC-2026-2430 Crawlee for Python: SSRF via sitemap-derived URLs

Overview - Vulnerability type: Blind SSRF - Affected components: src/crawlee/utils/sitemap.py, src/crawlee/utils/robots.py, src/crawlee/requestloaders/sitemaprequestloader.py, and all built-in HTTP clients. - Trigger: an attacker-controlled sitemap or robots.txt containing a URL that points to an...

PYSEC-2026-3060 Amazon SageMaker Python SDK is missing integrity verification in its Triton inference handler

Summary Amazon SageMaker Python SDK is an open-source library for training and deploying machine learning models on Amazon SageMaker. An issue exists where, under certain circumstances, the Triton inference handler deserializes model artifacts without performing integrity verification, allowing...

PYSEC-2026-3395 python-utcp: Full Process Environment Exposed to CLI Subprocess - Secrets Leakage via Command Injection

Summary prepareenvironment in clicommunicationprotocol.py passes a full copy of os.environ to every CLI subprocess. When combined with the Command Injection vulnerability CWE-78 in substituteutcpargs tracked as GHSA-33p6-5jxp-p3x4, an attacker can exfiltrate all process-level secrets in a single...

PYSEC-2026-3039 python-multipart has Denial of Service via unbounded multipart part headers

Summary python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual part header. An attacker could send a request with either many...

PYSEC-2026-2651 Mistune has a ReDoS in LINK_TITLE_RE that allows denial of service via crafted Markdown input

Summary A ReDoS Regular Expression Denial of Service vulnerability in LINKTITLERE allows an attacker who can supply Markdown for parsing to cause denial of service. A crafted 58-byte Markdown document blocks the parser for approximately 6 seconds measured on Apple M2, Python 3.14.3, with...

PYSEC-2026-2892 PPTAgent: Arbitrary Code Execution via Python eval() of LLM-Generated Code with Builtins in Scope

Summary This vulnerability has been fixed in https://github.com/icip-cas/PPTAgent/commit/418491a9a1c02d9d93194b5973bb58df35cf9d00. CodeExecutor.executeactions pptagent/apis.py:126-205 processes LLM-generated slide editing actions using Python's eval: python pptagent/apis.py:184-186 partialfunc =...

PYSEC-2026-2387 AWS Encryption SDK for Python: Key commitment policy bypass via shared key cache

Summary AWS Encryption SDK ESDK for Python is a client-side encryption library. An issue exists where, under certain circumstances, a specific cryptographic algorithm downgrade in the caching layer might allow an authenticated local threat actor to bypass key commitment policy enforcement via a...

pip Vulnerable to Inclusion of Functionality from Untrusted Control Sphere

pip prior to version 26.1 would run self-update check functionality after installing wheel files which required importing well-known Python modules names. These module imports were intentionally deferred to increase startup time of the pip CLI. The patch changes self-update functionality to run...

PYSEC-2026-2876 pip Vulnerable to Inclusion of Functionality from Untrusted Control Sphere

pip prior to version 26.1 would run self-update check functionality after installing wheel files which required importing well-known Python modules names. These module imports were intentionally deferred to increase startup time of the pip CLI. The patch changes self-update functionality to run...

PYSEC-2026-2890 Poetry has Path Traversal in tar extraction on Python 3.10.0 - 3.10.12 and 3.11.0 - 3.11.4

Summary The extractall function in src/poetry/utils/helpers.py:410-426 extracts sdist tarballs without path traversal protection on Python versions where tarfile.datafilter is unavailable. Considering only Python versions which are still supported by Poetry, these are 3.10.0 - 3.10.12 and 3.11.0 ...

PYSEC-2026-2331 AgentScope Vulnerable to Remote Code Injection

A vulnerability was determined in modelscope agentscope up to 1.0.18. Affected by this vulnerability is the function executepythoncode/executeshellcommand of the file src/AgentScope/tool/coding/python.py. This manipulation causes code injection. The attack is possible to be carried out remotely...

PYSEC-2026-3038 python-multipart affected by Denial of Service via large multipart preamble or epilogue data

Summary A denial of service vulnerability exists when parsing crafted multipart/form-data requests with large preamble or epilogue sections. Details Two inefficient multipart parsing paths could be abused with attacker-controlled input. Before the first multipart boundary, the parser handled...

PYSEC-2026-2583 LangSmith SDK: Streaming token events bypass output redaction

Summary The LangSmith SDK's output redaction controls hideOutputs in JS, hideoutputs in Python do not apply to streaming token events. When an LLM run produces streaming output, each chunk is recorded as a newtoken event containing the raw token value. These events bypass the redaction pipeline...