CVE-2026-18374
GNU C Library fopen Heap Buffer Overflow
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.
INFO
Published Date :
Aug. 27, 2026, 8:17 p.m.
Last Modified :
Aug. 27, 2026, 8:17 p.m.
Remotely Exploit :
No
Source :
3ff69d7a-14f2-4f67-a097-88dee7810d18
Affected Products
The following products are affected by CVE-2026-18374
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 3ff69d7a-14f2-4f67-a097-88dee7810d18 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update GNU C Library to a version later than 2.45.
- Validate 'ccs' input before passing to fopen.
- Avoid passing attacker-controlled strings to 'ccs'.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-18374.
| URL | Resource |
|---|---|
| https://sourceware.org/bugzilla/show_bug.cgi?id=34574 | |
| https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0015 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18374 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-18374
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-18374 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18374 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 3ff69d7a-14f2-4f67-a097-88dee7810d18
Aug. 27, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L Added CWE CWE-787 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/18xxx/CVE-2026-18374.json">CVE-2026-18374</a> Added Reference https://sourceware.org/bugzilla/show_bug.cgi?id=34574 Added Reference https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0015