# CVE-2026-20244: Cisco ClamAV integer overflow in DMG file parser

Source: https://junglewise.ai/threats/cve-2026-20244-cisco-clamav-integer-overflow-in-dmg-file-parser  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-01. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

CVE-2026-20244 · Severity: high · CVSS 7.5 · Published 2026-07-01

ClamAV is an open-source antivirus engine used to scan files for malicious content. A vulnerability in how it processes Apple Disk Image (DMG) files could allow an attacker to crash the scanning service by sending a specially crafted file. This results in a denial-of-service condition where the system can no longer scan new files for threats, and on Windows systems, it may require a manual reboot to restore operations.

## Quick answers

**Is CVE-2026-20244 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20244 being exploited in the wild.

**How severe is CVE-2026-20244?** High severity, with a CVSS score of 7.5, published 1 July 2026.

**Which products and versions are affected?** Cisco Systems, Inc. ClamAV; Cisco Systems, Inc. Secure Endpoint Connector for Windows Prior to 8.6.2; Cisco Systems, Inc. Secure Endpoint Connector for Linux Prior to 1.29.0; Cisco Systems, Inc. Secure Endpoint Connector for Mac Prior to 1.27.2.

**Is there a fix for CVE-2026-20244?** A patch was published on 2026-07-01: Fixed versions released for Cisco Secure Endpoint products. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-20244 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-20244?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This vulnerability (CWE-120) exists in the DMG file format parser of ClamAV due to improper boundary checks during file scanning. Specifically, the flaw can lead to an integer overflow on 32-bit platforms when processing crafted DMG content, resulting in memory corruption. An unauthenticated remote attacker can exploit this by providing a malicious DMG file to be scanned, causing the ClamAV process to terminate. While primarily a DoS risk, Cisco notes that memory corruption could potentially lead to other impacts, though modern 64-bit protections mitigate code execution risks. The vulnerability is patched in ClamAV and integrated Cisco Secure Endpoint products (e.g., Windows Connector 8.6.2).

## Affected products

- Cisco Systems, Inc. ClamAV
- Cisco Systems, Inc. Secure Endpoint Connector for Windows Prior to 8.6.2
- Cisco Systems, Inc. Secure Endpoint Connector for Linux Prior to 1.29.0
- Cisco Systems, Inc. Secure Endpoint Connector for Mac Prior to 1.27.2

## Timeline

- 2026-07-01: advisory: Cisco published the security advisory.
- 2026-07-01: patched: Fixed versions released for Cisco Secure Endpoint products.

## References

- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-88cFYyxR](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-88cFYyxR)