GHSA-P5WC-9W9R-M232 is a high-severity security vulnerability in ultimate-sitemap-parser (pip), affecting versions <= 1.8.0. It is fixed in 1.8.1.
XML Entity Expansion (Billion Laughs) DoS in XMLSitemapParser Summary ultimate-sitemap-parser version 1.8.0 and earlier parse attacker-controlled XML content using Python's xml.parsers.expat without any restriction on DTD declarations or recursive entity references. An attacker who can serve a malicious sitemap can trigger exponential XML entity expansion (the "Billion Laughs" attack), causing unbounded CPU and memory consumption in the victim process. No authentication, user interaction, or special configuration is required, the vulnerability is exploitable by default through any public-facing use of sitemaptreeforhomepage() or sitemapfromstr(). Details The vulnerable code path begins at the public API entry points and flows to the Expat XML parser without any sanitization: usp/tree.py:42, sitemaptreeforhomepage(homepageurl) is the primary public entry point. usp/tree.py:133, sitemapfromstr(content) is the secondary public entry point (also directly reachable from user code). usp/fetchparse.py:141-145, SitemapFetcher.fetch() retrieves the remote URL content. usp/fetchparse.py:175, The raw response becomes responsecontent (taint propagation point). usp/fetchparse.py:441-450, XMLSitemapParser.sitemap() creates an Expat parser and feeds the attacker-controlled content directly to it: A full audit of the usp/ directory confirms that none of the following hardening measures are present: defusedxml usage DOCTYPE rejection SetParamEntityParsing UseForeignDTD ExternalEntityRefHandler When a Billion Laughs payload is parsed, each nested entity reference is expanded recursively, multiplying the in-memory string by a factor of 10 per nesting level. At level 6 (10⁶ expansions), processing time exceeds 20 seconds, effectively hanging the calling process. PoC Environment setup: Attack payload and execution: Expected output (observed during dynamic reproduction): Processing time grows exponentially: level 5 is ~165× slower than level 4, and level 6 exceeds the 20-second watchdog. This conclusively demonstrates unbounded resource consumption. Impact This is a Denial-of-Service (DoS) vulnerability via XML Entity Expansion (the "Billion Laughs" / CWE-776 pattern). Any application or service that uses ultimate-sitemap-parser to crawl external or user-supplied URLs is impacted. Who is affected: Web crawlers and indexers that call sitemaptreeforhomepage() against arbitrary URLs, a single malicious sitemap server can lock up the crawler process. CI/CD pipelines and monitoring tools that periodically parse sitemaps as part of automated workflows. Any application that passes unvalidated user input to sitemapfrom_str(). Because no authentication, elevated privilege, or prior relationship is required (CVSS PR:N, UI:N), the attack surface is broad. An attacker only needs to operate a web server that returns a malicious sitemap when visited. Reproduction artifacts Dockerfile poc.py
GHSA-P5WC-9W9R-M232 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (1.8.1). Upgrading removes the vulnerable code path.
pip
ultimate-sitemap-parser (<= 1.8.0)ultimate-sitemap-parser → 1.8.1 (pip)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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Already deployed Kodem? See GHSA-P5WC-9W9R-M232 in your environment →Upgrade ultimate-sitemap-parser to 1.8.1 or later to resolve this vulnerability.
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GHSA-P5WC-9W9R-M232 is a high-severity security vulnerability in ultimate-sitemap-parser (pip), affecting versions <= 1.8.0. It is fixed in 1.8.1.
GHSA-P5WC-9W9R-M232 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
ultimate-sitemap-parser (pip) versions <= 1.8.0 is affected.
Yes. GHSA-P5WC-9W9R-M232 is fixed in 1.8.1. Upgrade to this version or later.
Whether GHSA-P5WC-9W9R-M232 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade ultimate-sitemap-parser to 1.8.1 or later.