---
id: CVE-2023-6780
title: 'Glibc: integer overflow in __vsyslog_internal()'
summary: >-
  An integer overflow was found in the __vsyslog_internal function of the glibc
  library. This function is called by the syslog and vsyslog functions. This
  issue occurs when these functions are called with a very long message, leading
  to an…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-131
vendor: Red Hat
product: glibc
affected:
  - glibc
  - compat-glibc
  - glibc
  - compat-glibc
  - glibc
  - glibc
  - glibc
  - glibc (all versions)
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-01-31T16:36:34.378685Z'
exploitAvailable: true
published: '2024-01-31'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:15:20.900Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-6780'
references:
  - url: >-
      http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
  - url: 'http://seclists.org/fulldisclosure/2024/Feb/3'
  - url: 'https://access.redhat.com/security/cve/CVE-2023-6780'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2254396'
    label: RHBZ#2254396
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G/
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWQ6BZJ6CV5UAW4VZSKJ6TO4KIW2KWAQ/
  - url: 'https://security.gentoo.org/glsa/202402-01'
  - url: 'https://www.openwall.com/lists/oss-security/2024/01/30/6'
  - url: 'https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt'
tags:
  - cve.org
  - exploit-available
epss: 0.02689
epssPercentile: 0.85585
ingestedAt: '2026-10-15T04:46:37.154Z'
---

## Overview

An integer overflow was found in the __vsyslog_internal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when these functions are called with a very long message, leading to an incorrect calculation of the buffer size to store the message, resulting in undefined behavior. This issue affects glibc 2.37 and newer.

## Affected

- `glibc`
- `compat-glibc`
- `glibc`
- `compat-glibc`
- `glibc`
- `glibc`
- `glibc`
- `glibc (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.