Vulnerability · Published Sep 28, 2026 · Assigned by glibc
CVE-2026-97399One-byte overread in strncasecmp on Power8
Low 3.7
In plain English
A low-severity security flaw in glibc from The GNU C Library. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | glibc | no fix listed | DEBIAN-CVE-2026-97399 |
| Debian:13 | glibc | no fix listed | DEBIAN-CVE-2026-97399 |
| Debian:14 | glibc | 2.43-7 | DEBIAN-CVE-2026-97399 |
| Ubuntu:22.04:LTS | glibc | no fix listed | UBUNTU-CVE-2026-97399 |
| Ubuntu:24.04:LTS | glibc | no fix listed | UBUNTU-CVE-2026-97399 |
| Ubuntu:26.04:LTS | glibc | no fix listed | UBUNTU-CVE-2026-97399 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The GNU C Library | glibc | 2.24 – before 2.45 |
Weakness: CWE-126 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L