CVE-2025-48769: Use After Free vulnerability was discovered in fs/vfs/fs_rename code of the Apache NuttX RTOS, that due recursive implementation and single buffer use by two di

Use After Free vulnerability was discovered in fs/vfs/fs_rename code of the Apache NuttX RTOS, that due recursive implementation and single buffer use by two di

Use After Free vulnerability was discovered in fs/vfs/fs_rename code of the Apache NuttX RTOS, that due recursive implementation and single buffer use by two different pointer variables allowed arbitrary user provided size buffer reallocation and write to the previously freed heap chunk, that in specific cases could cause unintended virtual filesystem rename/move operation results. This issue affects Apache NuttX RTOS: from 7.20 before 12.11.0. Users of virtual filesystem based services with write access especially when exposed over the network (i.e. FTP) are affected and recommended to upgrade to version 12.11.0 that fixes the issue.

Description from the National Vulnerability Database, published by security@apache.org

What it means for a small business

Apache NuttX RTOS runs on web servers, so this is mostly your hosting company's to fix. On shared hosting you can't patch it yourself, but you can ask.

Ask your host whether your server runs it, whether it's updated, and on what date. A good host answers that in a day.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 1.6%, higher than 75% of CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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