SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-18374

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…

MEDIUM 4.9EPSS 0.15%

Does this matter?

Lower severity and a low EPSS score (0.15%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
4.9 MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS
0.15% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-787
Source
3ff69d7a-14f2-4f67-a097-88dee7810d18

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.