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PatchSiren cyber security CVE debrief

CVE-2026-20244 Cisco CVE debrief

A vulnerability in the DMG 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 DMG files during scanning, which may result in an integer overflow on 32-bit platforms only. The vulnerability affects Cisco Secure Endpoint and ClamAV users, who should be aware of the high-severity risk and take immediate action to mitigate it.

Vendor
Cisco
Product
Secure Endpoint
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-01
Original CVE updated
2026-07-09
Advisory published
2026-07-01
Advisory updated
2026-07-09

Who should care

Users of Cisco Secure Endpoint and ClamAV, particularly those responsible for vulnerability management, system administration, and security operations, should be aware of this high-severity vulnerability. They should assess their exposure, review official advisories, and implement necessary mitigations to protect against potential exploitation.

Technical summary

The vulnerability is caused by improper boundary checks for content in DMG files during scanning, which may result in an integer overflow on 32-bit platforms only. An attacker could exploit this vulnerability by submitting a crafted file that contains DMG content to be scanned by ClamAV on an affected device. This could lead to a DoS condition or potentially other impacts due to memory corruption.

Defensive priority

High

Recommended defensive actions

  • Apply patches or updates provided by Cisco to fix the vulnerability
  • Implement compensating controls, such as monitoring and exception tracking
  • Conduct inventory checks to identify affected systems
  • Restrict access to DMG files and limit scanning to trusted sources
  • Review and enhance monitoring, detection, and logging for exposed assets
  • Track exceptions and retest remediated assets
  • Verify evidence of remediation and close the item only after documentation is complete

Evidence notes

The CVE record was published on 2026-07-01T17:16:30.593Z and was last modified on 2026-07-09T18:00:43.937Z. The NVD entry is currently Analyzed. Cisco Secure Endpoint and ClamAV users should verify their systems for potential exposure and review official advisories for mitigation strategies. Evidence is based on CVE and NVD information, which may have limitations in scope and detail.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-20244 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-20244

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-20244 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-20244

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.