Cisco Secure Endpoint up to 8.4.5.30483 ALZ File Format Parser buffer overflow

Summaryinfo

A vulnerability has been found in Cisco Secure Endpoint and classified as critical. This impacts an unknown function of the component ALZ File Format Parser. This manipulation causes buffer overflow. This vulnerability is tracked as CVE-2026-20243. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Cisco Secure Endpoint and classified as critical. Affected by this vulnerability is an unknown part of the component ALZ File Format Parser. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect availability. The summary by CVE is:

A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in ALZ files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains ALZ content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-20243 since 10/08/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/01/2026).

Upgrading eliminates this vulnerability.

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Productinfo

Vendor

• Cisco

Name

• Secure Endpoint

Version

• 1.6.0
• 1.7.0
• 1.8.0
• 1.8.1
• 1.8.4
• 1.9.0
• 1.9.1
• 1.10.0
• 1.10.1
• 1.10.2
• 1.11.0
• 1.11.1
• 1.12.0
• 1.12.1
• 1.12.2
• 1.12.3
• 1.12.4
• 1.12.5
• 1.12.6
• 1.12.7
• 1.13.0
• 1.13.1
• 1.13.2
• 1.14.0
• 1.14.1
• 1.15.0
• 1.15.1
• 1.15.2
• 1.15.3
• 1.15.4
• 1.15.5
• 1.15.6
• 1.16.0
• 1.16.1
• 1.16.2
• 1.16.3
• 1.17.0
• 1.17.1
• 1.17.2
• 1.18.0
• 1.18.1
• 1.19.0
• 1.20.0
• 1.20.1
• 1.20.2
• 1.20.3
• 1.20.4
• 1.20.5
• 1.20.6
• 1.20.7
• 1.20.8
• 1.21.0
• 1.21.1
• 1.21.2
• 1.21.3
• 1.22.0
• 1.22.1
• 1.22.2
• 1.22.3
• 1.22.4
• 1.23.0
• 1.23.1
• 1.24.0
• 1.24.1
• 1.24.2
• 1.24.3
• 1.24.4
• 1.24.5
• 1.25.0
• 1.25.1
• 1.25.2
• 1.26.0
• 1.26.1
• 1.27.0
• 1.27.1
• 1.27.2
• 6.0.7
• 6.0.9
• 6.1.5
• 6.1.7
• 6.1.9
• 6.2.1
• 6.2.3
• 6.2.5
• 6.2.9
• 6.2.19
• 6.3.1
• 6.3.3
• 6.3.5
• 6.3.7
• 7.0.5
• 7.1.1
• 7.1.5
• 7.2.3
• 7.2.5
• 7.2.7
• 7.2.11
• 7.2.13
• 7.3.1
• 7.3.3
• 7.3.5
• 7.3.9
• 7.3.13
• 7.3.15
• 7.4.1
• 7.4.1.20425
• 7.4.1.20439
• 7.4.3
• 7.4.3.20679
• 7.4.5
• 7.5.1.20813
• 7.5.1.20833
• 7.5.3
• 7.5.5
• 7.5.7
• 7.5.9
• 7.5.11
• 7.5.13.21586
• 7.5.13.21598
• 7.5.15.21611
• 7.5.17.21680
• 7.5.19
• 7.5.20
• 7.5.21.21732
• 8.0.1.21160
• 8.0.1.21164
• 8.1.3
• 8.1.3.21242
• 8.1.5
• 8.1.5.21322
• 8.1.7
• 8.1.7.21417
• 8.1.7.21512
• 8.1.7.21585
• 8.2.1.21612
• 8.2.1.21650
• 8.2.3.30119
• 8.2.4.30130
• 8.4.0
• 8.4.1.30298
• 8.4.1.30307
• 8.4.2.30317
• 8.4.3
• 8.4.4.30419
• 8.4.4.30467
• 8.4.5.30483

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Entryinfo

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