When `update-core.php` version scraping goes wrong — telling a plugin version number apart from WordPress core

On hosting without SSH access, a common pattern is to open update-core.php (the WordPress update screen) with Playwright and read "what version is WordPress core currently running" straight off the page text. In one deployment, the recorded core version came back as something like 1.7.11 — a number that has never existed for WordPress core. Note: update-core.php is the WordPress admin's "Updates" page, listing pending updates for core, plugins, themes, and translations all on one screen. What was actually happening That page doesn't only show the core version string — it's packed with version numbers belonging to pending plugin and translation updates too. A line like "Update Plugin X to 1.7.11" is typical. # First implementation — grabs the first N.N.N-shaped number on the page match = re . search ( r ' \d+\.\d+(?:\.\d+)? ' , page_text ) version = match . group ( 0 ) if match else None This naive regex grabs whatever N.N.N -shaped number appears first on the page. Because of how the page is laid out, a plugin's pending update can render above the core version message, so 1.7.11 (a plugin's version) ended up recorded as the WordPress core version. Why this is hard to catch The bug doesn't throw an exception — the regex matches successfully, just on the wrong value. Nothing about it looks broken until someone notices the report shows a version that WordPress core has never shipped (there's no 1.x series for core). The fix — a three-stage guard Prefer a dedicated selector first — look for specific DOM locations where core's update message actually renders, like p.response > strong or #wp-version-message strong Fall back to keyword-anchored regex — if no selector matches, only accept a number immediately following the words "WordPress," "バージョン," or "Version" Validate plausibility as a final check — whichever path produced a value, run it through a function that checks the major version number falls within 4–9 def is_plausible_wp_core_version ( ver : str ) -> bool : m =