Quick answers
- Is CVE-2026-98907 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-98907 being exploited in the wild.
- How severe is CVE-2026-98907?
- Informational severity, published 23 October 2026.
- Which products and versions are affected?
- Linux kernel multiple versions (fix applied across stable branches 4.x through 7.x).
- Is there a fix for CVE-2026-98907?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-98907 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-98907?
- Check whether you run Linux kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A race condition exists in btrfs's sb_write_pointer() function, which reads the superblock from the block device page cache using read_cache_page_gfp(). The function lacks synchronization against BLKBSZSET block size changes (a similar issue was previously fixed in commit 3f29d661e568). The fix adds filemap_invalidate_lock()/filemap_invalidate_unlock() calls around the read_cache_page_gfp() operation to serialize reads against block size modifications, preventing the function from accessing invalidated or stale page cache entries.
Affected products
- Linux Kernel multiple versions (fix applied across stable branches 4.x through 7.x)
Timeline
- 2026-10-23: disclosed: Public disclosure via NVD and stable kernel tree