Buffer overflow in Cisco Secure Endpoint
CVE-2026-20243
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (45.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Cisco Secure Endpoint — versions 7.0.5, 6.2.19, 7.3.3
- Cisco Secure Endpoint
- Clamav
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20243?
- CVE-2026-20243 is a high-severity vulnerability in Cisco Secure Endpoint, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.5/10. Published 2026-07-01.
- How severe is CVE-2026-20243?
- High severity. CVSS v3 base score is 7.5 out of 10.