CVE-2026-18374EPSS p3.1%
CVE-2026-18374CVE-2026-18374
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.
Scoring
| CVSS | 4.9 () |
| Vector | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L |
| EPSS | 0.14% probability of exploitation · percentile 3.1% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-03 |