# CVE-2026-97399: One-byte overread in strncasecmp on Power8

CVE-2026-97399 is fixed in glibc on 1 platform, first by DEBIAN-CVE-2026-97399, released October 11, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-97399
- Priority: Routine
- CVSS: 3.7 (Low)
- EPSS: 0.0028
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 28, 2026
- Weakness: Buffer Over-read
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97399

## Description

The strncasecmp function in the GNU C Library 2.24 and later optimized for the Power8 architecture may read one byte beyond the input size limit, which may crash a program when that byte is not readable.  This condition may happen when the input strings to the strncasecmp function are attacker controlled in an application and they match all the way up to the edge of their page and the neighbouring page is either not mapped or is not readable.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | glibc Debian 14 | 2.43-7 | [DEBIAN-CVE-2026-97399](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97399.md) | Oct 11, 2026 |
| Linux | glibc sles 15.6 | 2.38-150600.14.61.1 | [SUSE-SU-2026:4656-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4656-1.md) | Nov 7, 2026 |
| Linux | glibc sles 15.7 | 2.38-150600.14.61.1 | [SUSE-SU-2026:4656-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4656-1.md) | Nov 7, 2026 |

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Data as of 2026-11-08T19:12:23Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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