# CVE-2026-97548: xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions

CVE-2026-97548 is fixed in linux on 1 platform by DEBIAN-CVE-2026-97548 (version 7.2.7-1), released October 2, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-97548
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97548

## Description

In the Linux kernel, the following vulnerability has been resolved:  xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions  The _maxlevels_ondisk functions are used to compute the size of in-memory btree cursors for each btree type.  Unfortunately, LOLLM noticed that the rtrmap and rtrefcount versions of these functions forget to account for the inode root, which means that we could access beyond the end of the cursor given a sufficiently large btree.  Fix this.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-97548](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97548.md) | Oct 2, 2026 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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