CVE-2026-5450

9.8

CRITICAL CVSS 3.1

scanf %mc off-by-one heap buffer overflow

Overview

Description

Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.

Details

INFO

Published Date :

April 20, 2026, 9:16 p.m.

Last Modified :

April 23, 2026, 3:33 p.m.

Remotely Exploit :

Yes !

Source :

3ff69d7a-14f2-4f67-a097-88dee7810d18

Impact

Affected Products

The following products are affected by CVE-2026-5450 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.

ID	Vendor	Product	Action
1	Gnu	glibc

: Total Affected Vendor : 1 | Products : 1

Scoring

CVSS Scores

The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.

Score	Version	Severity	Vector	Exploitability Score	Impact Score	Source
	CVSS 3.1	CRITICAL				134c704f-9b21-4f2e-91b3-4a467353bcc0

Solution

Update the GNU C Library to a version that fixes the heap buffer overflow vulnerability.

Update the GNU C Library to a non-vulnerable version.
Recompile applications linked against the library.

Public PoC/Exploit Available at Github

CVE-2026-5450 has a 2 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References

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-2026-5450.

URL	Resource
https://inbox.sourceware.org/libc-announce/[email protected]/T/#u	Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450	Exploit Issue Tracking
https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450	Exploit Issue Tracking

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-5450 is associated with the following CWEs:

CWE-122: Heap-based Buffer Overflow

CWE-787: Out-of-bounds Write

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-2026-5450 weaknesses.

CAPEC-92: Forced Integer Overflow Forced Integer Overflow

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).

typhoon1217/linux_security_kit

security scan and patch for linux system

Shell

Updated: 1 week, 1 day ago

0 stars 0 fork 0 watcher

Born at : May 2, 2026, 10:19 a.m. This repo has been linked 12 different CVEs too.

akikr/demo-postgres-app

This project provides a simple example of Spring Boot CRUD application with Postgres DB, docker-compose and LGTM Observability support

docker docker-compose grafana jdbc lgtm-stack makefile postgres spring-boot

Makefile Shell Dockerfile Java

Updated: 1 day, 14 hours ago

0 stars 0 fork 0 watcher

Born at : Nov. 20, 2025, 7:29 p.m. This repo has been linked 51 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-5450 vulnerability anywhere in the article.

Daily CyberSecurity

Three Silent Vulnerabilities Discovered in the glibc Core

The core of many Linux-based operating systems is facing a series of security challenges. Recent advisories for the GNU C Library (glibc) have disclosed three distinct vulnerabilities ranging from hea ...

Published Date: Apr 21, 2026 (2 weeks, 6 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-5450 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.

Initial Analysis by [email protected]

Apr. 23, 2026

Action	Type	New Value
Added	CWE	CWE-787
Added	CPE Configuration	OR cpe:2.3:a:gnu:glibc::::::::* versions from (including) 2.7 up to (including) 2.43
Added	Reference Type	GNU C Library: https://inbox.sourceware.org/libc-announce/[email protected]/T/#u Types: Third Party Advisory
Added	Reference Type	CISA-ADP: https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450 Types: Exploit, Issue Tracking
Added	Reference Type	GNU C Library: https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450 Types: Exploit, Issue Tracking

CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

Apr. 21, 2026

Action	Type	Old Value	New Value
Added	CVSS V3.1		AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Added	Reference		https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450

New CVE Received by 3ff69d7a-14f2-4f67-a097-88dee7810d18

Apr. 20, 2026

Action	Type	New Value
Added	Description	Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
Added	CWE	CWE-122
Added	Reference	https://inbox.sourceware.org/libc-announce/[email protected]/T/#u
Added	Reference	https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.