CVE-2026-18374
Published: September 3, 2026Last modified: September 7, 2026
Description
Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled. This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4.9 |
| Attack Vector | LOCAL |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | LOW |
| Vector | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | glibc | Fixed (2.37.0-r27) |
| 25 LTS | glibc | Fixed (2.39.0-r13) | |
| Stream | glibc | Fixed (2.43.0-r7) | |
| Hardened Containers | 23 LTS | glibc | Fixed (2.37.0-r27) |
| 25 LTS | glibc | Fixed (2.39.0-r13) | |
| Stream | glibc | Unknown (2.37.0-r0) |