# CVE-2026-98872: freevxfs: don't BUG() on unknown typed-extent type

CVE-2026-98872 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-98872, released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-98872
- Priority: Routine
- CVSS: 5.5 (Moderate)
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 23, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98872

## Description

In the Linux kernel, the following vulnerability has been resolved:  freevxfs: don't BUG() on unknown typed-extent type  vxfs_bmap_typed() handles four typed-extent types and calls BUG() in its default case, so an on-disk typed extent with any other type value crashes the kernel. It is reachable from ioctl(FIBMAP) on a regular file:    kernel BUG at fs/freevxfs/vxfs_bmap.c:230!   RIP: vxfs_bmap_typed fs/freevxfs/vxfs_bmap.c:230 [inline]        vxfs_bmap1+0x128a/0x12d0 fs/freevxfs/vxfs_bmap.c:257  Replace the BUG() with WARN_ON_ONCE() and return 0 -- the value vxfs_bmap_typed() already returns on failure (and from the DEV4 case above); vxfs_getblk() maps 0 to -EIO, so the ioctl fails cleanly.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-98872](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98872.md) | Oct 24, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-98872](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98872.md) | Oct 24, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-98872](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98872.md) | Oct 24, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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